Dual Passports

[seasider]

Heres the situation :

Thai national living in the UK, already a British Citizen with a valid,British passport. Thai Passport has expired or been damaged,so needs to be renewed.

The person concerned is going back to live and work in Thailand and will, occasionally, be travelling to different regions of asia, therefore,it would be much more convenient to use a British Passport(no hassle concerning visas).

The person wants to go back to Thailand on her British passport and apply for a new Thai passport when in Thailand. This i think would have to be done within a month as her 30 day stamp on arrival would expire. Her idea was to then go to Poipet and cross the border ,leaving Thailand on her British passport and then leaving Cambodia on her British passport and entering Thailand on her Thai passport.

The problem is, then ,when she leaves Thailand again on her British passport,(which she needs to do to travel to certain countries) there wont be any record of her being stamped in on her British passport , as she entered Thailand from Cambodia on her Thai passport.

Am i missing something? Is there an easier way around this, other than her renewing her Thai passport in the uk? As said previously she would rather do that in Thailand.

Thanks for any advice in advance

[Mossfinn]

Previous thread

Including crossing land borders in Asia

[Mario2008]

She should apply for a new passport at the Thai embassy. When she enters Thailand on a Britisch passport she will be considered to be a Brit for immigration purposes and will need to have a visa and extension of stay till she leaves Thailand on her Britisch passport and re-enters on her Thai passport.

getting a Thai passport in Thailand will also rquire her to be registered on somones household book. If she leaves for Thailand on her UK passport without a Thai passport or a visa she will need to show a return ticket or risk being denied boarding.

Note that she probably can't use a damaged Thai passport, but she can use an expired passport to enter Thailand.

[seasider]

She should apply for a new passport at the Thai embassy. When she enters Thailand on a Britisch passport she will be considered to be a Brit for immigration purposes and will need to have a visa and extension of stay till she leaves Thailand on her Britisch passport and re-enters on her Thai passport.

getting a Thai passport in Thailand will also rquire her to be registered on somones household book. If she leaves for Thailand on her UK passport without a Thai passport or a visa she will need to show a return ticket or risk being denied boarding.

Note that she probably can't use a damaged Thai passport, but she can use an expired passport to enter Thailand.

Didn't know you could use an expired Thai passport to enter Thailand. For arguements sake, lets say she cant get her thai passport in the uk(lack of time etc). What happens when she re-enters Thailand on her thai passport and then wants to leave Thailand again? What passport would she leave Thailand on, her Thai one? and then i presume she would switch to her British one upon arrival.

[fvw53]

If it is legal to have double nationality (Thai and UK) which I think it is, then this person should enter Thailand on her old Thai passport and take a house registration.

Indeed an expired or damaged Thai passport does not have an impact on her status of being a Thai national.

I recommend she applies for a new Thai passport at the Foreign Ministry and again I see no reason why the delivery of a new passport would be take more than the ususal waiting time (few days).

If then later she wants to travel to countries which require a visa for a Thai national but not for a UK national then she should show at check-in her UK passport to the airline staff to explain she requires no visa.

At Immigration desk she should simply go in the line of Thai nationals.

Now one Thai friend says that at the Immigration desk they may question why she has no visa for the destination indicated on the boarding pass : I cannot imagine why Thai Immigration would be worried about her rights to enter another country.......

[ThaiVisaExpress]

Simply renew in the UK i cant see an issue.

[7by7]

Quite. Renew the Thai passport at the RTE in London (took about a week when my wife did it) and then use the UK passport to enter and leave the UK and the Thai one to enter and leave Thailand; plus whichever one is easier for other countries. Thousands of people do this all the time without any problems.

[nakachalet]

my friend mario888

and so, what sayeth thou on the poster's major concern which has eluded most posters' responses....

The problem is, then ,when she leaves Thailand again on her British passport,(which she needs to do to travel to certain countries) there wont be any record of her being stamped in on her British passport , as she entered Thailand from Cambodia on her Thai passport.

....the lady standing on the soil of the kingdom and is holding a valid british passport with no record of her ever entering the kingdom.... how is she going to explain to the EXIT immigration officers at the port, of having no entry stamp....

but on the other hand, she has all the rights in the world to stand here, live here and enjoy her family members here.... cause she is thai by birth and on official record as such....

what would you suggest my friend?

Edited August 28, 2009 by nakachalet

[TerryLH]

Leave on the Thai passport.

Use whichever passport is best for her (visa wise) when going to other countries.

If the UK, the UK passport.

[7by7]

I can't speak for Mario, but I'll tell you what my wife and daughter both do; actually I already have, but I'll repeat it:_

Enter and leave Thailand on the Thai passport; enter and leave the UK on the British passport. Whichever passport one chooses for third party countries is a personal choice.

When leaving a country passport control of that country are only concerned that one has been there legally and not overstayed, so will only want to check the same passport one entered on.

When entering a country that country's passport control aren't interested in where one's come from. merely that one can legally enter that country, so previous stamps are irrelevant.

The solution to the OP's 'problem' is to renew the Thai passport before leaving the UK. They can enter Thailand on their Thai passport; leave Thailand on their Thai passport; enter Cambodia on their British passport (if they wish, isn't a Thai one better here?) leave Cambodia on the same one they used to enter and enter Thailand on their Thai one.

Edited August 28, 2009 by 7by7

[donx]

As others have posted, if at all possible get the Thai passport renewed in the UK. We did it in the US and we got them back in less than a month. 3 of the passports were renewing expired passports. 1 of the passports was a new application.

If the passport absolutely can't be renewed before returning to Thailand, then either enter Thailand on the expired passport (I don't know if that is possible but it does hurt to try) or enter on the UK passport. If immigration doesn't accept the expired Thai passport and the UK passport has to be shown (do so only as a last resort), then the best thing to do is to quickly renew the Thai passport. Once it is received leave Thailand using the UK passport. Then return the next day using the Thai passport.

[Maestro]

nakachalet, the answers to the OP’s question and to all you questions are in the link given by Mossfinn in this post:

http://www.thaivisa.com/forum/Dual-Passpor...35#entry2973835

Please read the linked post. There really is no need to rehash everything here for you.

--

Maestro

[seasider]

my friend mario888

and so, what sayeth thou on the poster's major concern which has eluded most posters' responses....

The problem is, then ,when she leaves Thailand again on her British passport,(which she needs to do to travel to certain countries) there wont be any record of her being stamped in on her British passport , as she entered Thailand from Cambodia on her Thai passport.

....the lady standing on the soil of the kingdom and is holding a valid british passport with no record of her ever entering the kingdom.... how is she going to explain to the EXIT immigration officers at the port, of having no entry stamp....

but on the other hand, she has all the rights in the world to stand here, live here and enjoy her family members here.... cause she is thai by birth and on official record as such....

what would you suggest my friend?

Ah, thanks Nakachalet, you seem to have understood what my/her concerns are. I appreciate all the responses but as i have said,she would rather not,actually probably cannot renew her thai passport in the uk(for various reasons including lack of time).

So as i said in the OP, after she enters Thailand on her British passport and renews her thai passport in Thailand and then goes to Cambodia, leaving Thailand on her British passport and then leaving Cambodia on her British passport but entering Thailand on her Thai passport,what happens the next time she leaves Thailand on her British passport? As Nakachalet outlined, she came in to Thailand from cambodia on her Thai passport, so there is no record of her entering Thailand on her British passport, so how could she leave on it?

Maybe she could leave on her Thai passport and show her British passport to check-in and immigration when arriving in Hong Kong/Japan/Singapore or wherever.

[seasider]

nakachalet, the answers to the OP’s question and to all you questions are in the link given by Mossfinn in this post:

http://www.thaivisa.com/forum/Dual-Passpor...35#entry2973835

Please read the linked post. There really is no need to rehash everything here for you.

--

Maestro

Ok, just seen this, i will have a look, thanks.

[seasider]

nakachalet, the answers to the OP’s question and to all you questions are in the link given by Mossfinn in this post:

http://www.thaivisa.com/forum/Dual-Passpor...35#entry2973835

Please read the linked post. There really is no need to rehash everything here for you.

--

Maestro

Ok, just seen this, i will have a look, thanks.

Seem to have the answers i won't, except for one scenario:

After arriving in Thailand on a british passport and then getting a new Thai passport in Thailand, the thai national stays and works in Thailand for say, 6 months,and then leaves Thailand on her Thai passport(with the intention to swap to her British passport before arriving at her destination),what happens to the overstay on her British passport?

Surely, she would have 5 months overstay on her British passport?

Wouild this be a problem as she might have to show that to check-in /immigration upon leaving Thailand to prove she can enter the destination country.

[7by7]

A Thai national entering Thailand on a non Thai, for example British, passport is treated for immigration purposes as a non Thai. So if they overstayed they would be subject to the same overstay rules and fines as any other non Thai.

If they obtained a new Thai passport whilst in Thailand and used that to leave the Kingdom then they would have an entry stamp in their British passport without a corresponding exit stamp, which could cause problems at a later date.

The advice is simple, dual Thai /another state nationals should always enter and leave Thailand using their Thai passport. If this is not possible, and I fail to see why it wouldn't be, then they should leave the kingdom, or any country, using the same passport as they entered on.

Leaving Thailand with their British passport and then re-entering with their new Thai one could cause problems as they would be entering Thailand with a passport issued in Thailand which did not have a Thai exit stamp in it.

Better, I think, to renew their Thai passport in London before leaving the UK and use that to enter and leave Thailand.

[samran]

nakachalet, the answers to the OP’s question and to all you questions are in the link given by Mossfinn in this post:

http://www.thaivisa.com/forum/Dual-Passpor...35#entry2973835

Please read the linked post. There really is no need to rehash everything here for you.

--

Maestro

Ok, just seen this, i will have a look, thanks.

Seem to have the answers i won't, except for one scenario:

After arriving in Thailand on a british passport and then getting a new Thai passport in Thailand, the thai national stays and works in Thailand for say, 6 months,and then leaves Thailand on her Thai passport(with the intention to swap to her British passport before arriving at her destination),what happens to the overstay on her British passport?

Surely, she would have 5 months overstay on her British passport?

Wouild this be a problem as she might have to show that to check-in /immigration upon leaving Thailand to prove she can enter the destination country.

To be honest, I'd delay the trip to get a new passport re-issued in London, to save a massive amount of hassel late down the track. Either that, or make sure she enters Thailand on the expired passport, and gets a new one re-issued while in Thailand. You are talking about three weeks at most via the embassy in London. If living in Thailand, the last thing you want to do is have immigration, work permit and visa hassels, especially if you don't 'have' to have them....

Also, I sounds like you are also not understanding a couple of points:

- Thai immigration doesn't decide if you have the 'right' to enter another country. That is a job for the airline check in. To do this, the traveller simply presents the check-in person BOTH passports. The UK passport will usually guarantee visa free entry into most western countries. The airline will then issue a boarding pass.

- As others have said, the Thai passport will be used to exit, and re-enter Thailand. British passport used to enter and exit most other countries.

- Having said that, the Thai passport is probably more advantageous to use around in and around Asia. The reason for this is Thai's are usually granted visa free entry in most other Asean countries, some which would require a British passport to get a visa (Vietnam, Indonesia). Where visa's are needed for both British and Thai passports, they are usually granted faster and cheaper for the Thai passport, if applying at that embassy in Bangkok. This is certainly true for travel to mainland China or India. If travelling often in stamp and visa happy Asia, a Thai passport only costs 1000 baht to replace when filled. I think a British passport requires you to remortgage your house.

- Also, 'swapping' passports is pretty well impossible at Asian land borders, so the 'passport swap' at Poipet isn't going to work.

Edited August 29, 2009 by samran

[seasider]

nakachalet, the answers to the OP’s question and to all you questions are in the link given by Mossfinn in this post:

http://www.thaivisa.com/forum/Dual-Passpor...35#entry2973835

Please read the linked post. There really is no need to rehash everything here for you.

--

Maestro

Ok, just seen this, i will have a look, thanks.

Seem to have the answers i won't, except for one scenario:

After arriving in Thailand on a british passport and then getting a new Thai passport in Thailand, the thai national stays and works in Thailand for say, 6 months,and then leaves Thailand on her Thai passport(with the intention to swap to her British passport before arriving at her destination),what happens to the overstay on her British passport?

Surely, she would have 5 months overstay on her British passport?

Wouild this be a problem as she might have to show that to check-in /immigration upon leaving Thailand to prove she can enter the destination country.

To be honest, I'd delay the trip to get a new passport re-issued in London, to save a massive amount of hassel late down the track. Either that, or make sure she enters Thailand on the expired passport, and gets a new one re-issued while in Thailand. You are talking about three weeks at most via the embassy in London. If living in Thailand, the last thing you want to do is have immigration, work permit and visa hassels, especially if you don't 'have' to have them....

Also, I sounds like you are also not understanding a couple of points:

- Thai immigration doesn't decide if you have the 'right' to enter another country. That is a job for the airline check in. To do this, the traveller simply presents the check-in person BOTH passports. The UK passport will usually guarantee visa free entry into most western countries. The airline will then issue a boarding pass.

- As others have said, the Thai passport will be used to exit, and re-enter Thailand. British passport used to enter and exit most other countries.

- Having said that, the Thai passport is probably more advantageous to use around in and around Asia. The reason for this is Thai's are usually granted visa free entry in most other Asean countries, some which would require a British passport to get a visa (Vietnam, Indonesia). Where visa's are needed for both British and Thai passports, they are usually granted faster and cheaper for the Thai passport, if applying at that embassy in Bangkok. This is certainly true for travel to mainland China or India. If travelling often in stamp and visa happy Asia, a Thai passport only costs 1000 baht to replace when filled. I think a British passport requires you to remortgage your house.

- Also, 'swapping' passports is pretty well impossible at Asian land borders, so the 'passport swap' at Poipet isn't going to work.

Ok, thanks for that. I have understood everything thats been posted regarding this, indeed,i have already told her to renew her Thai passport here in the uk. She wants to leave in a week or two to start new employment in Thailand, so she is limited for time,if she wasn't i would not have even raised the issue on here.

Was just seeing if there was another way round the problem by getting a new Thai passport in Thailand.

I am familiar in how to use dual passports, my own wife has both a Thai and British passport(dual citizenship) and she has used both in the ways suggested on here for many years.

I guess, even if she was on overstay on her British passport,if she departed Thailand on her new Thai passport,only needing to show check-in her British passport to allow her to fly to certain countries(Japan,for example) then Thai immigration would never even see her British passport,so the overstay would never be an issue.

Anyway, i have advised her to delay her return to Thailand and get her new Thai passport here in the uk,which i think she is now going to do, to save any hassles in the future.

Thanks for all the advice, much appreciated.

[KayT]

Heres the situation :

Thai national living in the UK, already a British Citizen with a valid,British passport. Thai Passport has expired or been damaged,so needs to be renewed.

The person concerned is going back to live and work in Thailand and will, occasionally, be travelling to different regions of asia, therefore,it would be much more convenient to use a British Passport(no hassle concerning visas).

The person wants to go back to Thailand on her British passport and apply for a new Thai passport when in Thailand. This i think would have to be done within a month as her 30 day stamp on arrival would expire. Her idea was to then go to Poipet and cross the border ,leaving Thailand on her British passport and then leaving Cambodia on her British passport and entering Thailand on her Thai passport.

The problem is, then ,when she leaves Thailand again on her British passport,(which she needs to do to travel to certain countries) there wont be any record of her being stamped in on her British passport , as she entered Thailand from Cambodia on her Thai passport.

Am i missing something? Is there an easier way around this, other than her renewing her Thai passport in the uk? As said previously she would rather do that in Thailand.

Thanks for any advice in advance

As far as dual nationality is concerned.It is frowned upon and it is usual that you cannot hold a Thai and other nationality passport after the age of 18.If it is found to be so then the person in question may be stripped of Thai citizenship.

I would suggest getting a new Thai passport in Britain and then using it to enter Thailand and keeping the British passport for out of the country journeys to make it so you dont have to get a visa in those countries that accept British citizens without a visa.

[plaaduk]

Heres the situation :

Thai national living in the UK, already a British Citizen with a valid,British passport. Thai Passport has expired or been damaged,so needs to be renewed.

The person concerned is going back to live and work in Thailand and will, occasionally, be travelling to different regions of asia, therefore,it would be much more convenient to use a British Passport(no hassle concerning visas).

The person wants to go back to Thailand on her British passport and apply for a new Thai passport when in Thailand. This i think would have to be done within a month as her 30 day stamp on arrival would expire. Her idea was to then go to Poipet and cross the border ,leaving Thailand on her British passport and then leaving Cambodia on her British passport and entering Thailand on her Thai passport.

The problem is, then ,when she leaves Thailand again on her British passport,(which she needs to do to travel to certain countries) there wont be any record of her being stamped in on her British passport , as she entered Thailand from Cambodia on her Thai passport.

Am i missing something? Is there an easier way around this, other than her renewing her Thai passport in the uk? As said previously she would rather do that in Thailand.

Thanks for any advice in advance

As far as dual nationality is concerned.It is frowned upon and it is usual that you cannot hold a Thai and other nationality passport after the age of 18.If it is found to be so then the person in question may be stripped of Thai citizenship.

I would suggest getting a new Thai passport in Britain and then using it to enter Thailand and keeping the British passport for out of the country journeys to make it so you dont have to get a visa in those countries that accept British citizens without a visa.

If you say that you may be stripped of your THai citizenship after the age of 18,if you hold the citizenship of another country, then it means Thailand does not recognise dual nationality!If you are issued a passport of another country, it means you have been bestowed the nationality of that country!Can anyone therefore confirm that Thailand recognises and accepts dual nationality?

[samran]

Heres the situation :

Thai national living in the UK, already a British Citizen with a valid,British passport. Thai Passport has expired or been damaged,so needs to be renewed.

The person concerned is going back to live and work in Thailand and will, occasionally, be travelling to different regions of asia, therefore,it would be much more convenient to use a British Passport(no hassle concerning visas).

The person wants to go back to Thailand on her British passport and apply for a new Thai passport when in Thailand. This i think would have to be done within a month as her 30 day stamp on arrival would expire. Her idea was to then go to Poipet and cross the border ,leaving Thailand on her British passport and then leaving Cambodia on her British passport and entering Thailand on her Thai passport.

The problem is, then ,when she leaves Thailand again on her British passport,(which she needs to do to travel to certain countries) there wont be any record of her being stamped in on her British passport , as she entered Thailand from Cambodia on her Thai passport.

Am i missing something? Is there an easier way around this, other than her renewing her Thai passport in the uk? As said previously she would rather do that in Thailand.

Thanks for any advice in advance

As far as dual nationality is concerned.It is frowned upon and it is usual that you cannot hold a Thai and other nationality passport after the age of 18.If it is found to be so then the person in question may be stripped of Thai citizenship.

I would suggest getting a new Thai passport in Britain and then using it to enter Thailand and keeping the British passport for out of the country journeys to make it so you dont have to get a visa in those countries that accept British citizens without a visa.

just goes to show you've never read the Thai nationality law.

Thailand has no issues with people with dual nationality, so far as people who are born with dual nationality, those who take on take on their spouses nationality and those who naturalise as Thai's, keeping their own nationality. Relaxing of laws regarding dual nationality occured in 1992, and laws liberalising access to Thai nationality for some occured in 2008.

Thai law only mentions that children born to a foreign parent and a thai parent, between the ages of 20 and 21 have the opportunity to renounce Thai nationality, if they so wish. There is no compulsion to do so, and no penalty if no choice is made. The number '18' is not mentioned anywhere in the law. This has been confirmed time and again in public statments by immigration officals.

Edited August 30, 2009 by samran

[p_brownstone]

As far as dual nationality is concerned.It is frowned upon and it is usual that you cannot hold a Thai and other nationality passport after the age of 18.If it is found to be so then the person in question may be stripped of Thai citizenship.

You are totally incorrect.

I suggest you do not Post or comment on topics you do not understand.

Patrick

[Hanimal]

As far as dual nationality is concerned.It is frowned upon and it is usual that you cannot hold a Thai and other nationality passport after the age of 18.If it is found to be so then the person in question may be stripped of Thai citizenship.

You are totally incorrect.

I suggest you do not Post or comment on topics you do not understand.

Patrick

And the real answer according to you is...?

[Mario2008]

As far as dual nationality is concerned.It is frowned upon and it is usual that you cannot hold a Thai and other nationality passport after the age of 18.If it is found to be so then the person in question may be stripped of Thai citizenship.

You are totally incorrect.

I suggest you do not Post or comment on topics you do not understand.

Patrick

And the real answer according to you is...?

As usual on this subject the corect answer is given by Samran.

[7by7]

Just like to point out that Samran's answer is not the real answer according to Samran.

It is the real answer according to Thai law!

[Halffull]

Just like to point out that Samran's answer is not the real answer according to Samran.

It is the real answer according to Thai law!

Hello guys,

Been following this thread carefully but still unclear. So I'm sorry if I make you go over this again. I am in a similar boat with KT's friend. I entered Thailand with my US Passport and while here I got a new Thai Passport. What will happen if I leave Thailand using my new Thai Passport with no entry stamp? Will it cause a problem with US Customs or Thai Customs, if any?

[ubonjoe]

Hello guys,

Been following this thread carefully but still unclear. So I'm sorry if I make you go over this again. I am in a similar boat with KT's friend. I entered Thailand with my US Passport and while here I got a new Thai Passport. What will happen if I leave Thailand using my new Thai Passport with no entry stamp? Will it cause a problem with US Customs or Thai Customs, if any?

You will not have a problem getting back into the states or leaving here.

The problem will be that yoo will have an entry into Thailand that does not show a departure in your US passport.

Best to use the US passport when you leave.

[Mario2008]

Just like to point out that Samran's answer is not the real answer according to Samran.

It is the real answer according to Thai law!

Hello guys,

Been following this thread carefully but still unclear. So I'm sorry if I make you go over this again. I am in a similar boat with KT's friend. I entered Thailand with my US Passport and while here I got a new Thai Passport. What will happen if I leave Thailand using my new Thai Passport with no entry stamp? Will it cause a problem with US Customs or Thai Customs, if any?

If you enter on your US passport and leave on your Thai passport for administrative purposes you will not have left Thailand and as far as immigration is concernd you as a US national will continue to be in Thailand.

You will have to leave on your US passport and next time you return enter on your Thai passport. From your US passport immigration will understand why you don't have an exit stamp from Thailand in your Thai passport.

[mpetersen]

my friend mario888

and so, what sayeth thou on the poster's major concern which has eluded most posters' responses....

The problem is, then ,when she leaves Thailand again on her British passport,(which she needs to do to travel to certain countries) there wont be any record of her being stamped in on her British passport , as she entered Thailand from Cambodia on her Thai passport.

....the lady standing on the soil of the kingdom and is holding a valid british passport with no record of her ever entering the kingdom.... how is she going to explain to the EXIT immigration officers at the port, of having no entry stamp....

but on the other hand, she has all the rights in the world to stand here, live here and enjoy her family members here.... cause she is thai by birth and on official record as such....

what would you suggest my friend?

Just enter and leave Thailand on your Thai passport. For the airline's purpose, show the UK passport if travelling, say, to Britain, so they don't deny boarding for lack of a visa.

Just because you leave Thailand on a Thai passport doesn't mean you have to enter the next country on your Thai passport also.

I do this myself when travelling to Europe, I leave on a home passport and enter on a EU passport, then when I leave I show exit immigration my EU passport, but the airline sees my home passport which I also use to enter back to my home country.

It's really quite simple.

[roamer]

A recent tale, two weeks ago in fact.

We had a nice holiday in Los, the wife as usual leaving UK on UK passport and entering Thailand on her Thai passport. All fine until we turned up to go home at check in desk...problem wife's Thai passport was out of date, on inspection it had expired one week before we entered. Airline said no way could she leave on UK passport, a bit of an argument ensued and we got taken through to see immigration who hummed and haa'ed a liitle and said ok they would allow it. Went back to check in with immigration who said ok to complete consternation of check in staff, I'm ear-wigging conversation and turns out flight was overbooked and they had let the seat go to a standby passenger. Supervisor disappears and returns with another immigration officer who says no we can't travel. I start to copy his name down from his badge which he then promptly covers up and tells me I can,t have his name. "Why not?" Answer, wait for it, ...."Because I'm on duty" !!!

I'm going to truncate this as I'm still might p***ed off about the whole thing but it ended up with the wife having to spend another 6 days in Bangkok getting another passport and paying out £200 for flight change and me & daughter flying home alone.

Moral of the story is I guess, if you only fish that Thai passport out of the drawer for trips home like us, do check the expiry date as it won't be checked if your leaving the UK on your British passport and you certainly can't rely on them telling you, or more likely, even noticing its expired when you get to immigration in Thailand. And remember unlike the UK passport its only valid for 5 years, that was our undoing.

For what its worth my wife's uncle who is a pretty high civil servant later contacted immigration who told him that the immigration officers can use their discretion in such cases and will usually allow travel. But its the golden rule you should never break....make sure an airline never has a chance to bump you if they are overbooked, because sure as hel_l they will to avoid having to compensate passengers whose docs are in order. Incidentally another of the passengers bumped had her UK leave to remain in old passport and not in her new passport, a common occurrence and usually no problem but was on this occasion.