My passport expires in April 2023

My Visa extension based on marriage is due January 6 2023

I am assuming but not absolutely certain, that in order to extend the Visa I need six months validity on a passport.

Is that correct?

Would be grateful if someone could confirm this one way or another.

Any extension will only be give for the remaining period of the passport. So 3 months in your case . I suggest you get a new passport  if you want the full year, and apply for it 4-5 months BEFORE given the current passport situation. (If UK)

To apply for a 12 month extension of stay (it is not a visa) if you do not have a passport valid for 12 months your extension will be issued to the day it expires. Then when you get a new passport you will have to apply for a new extension.

There is no 6 month rule for extensions of stay. The 6 month rule is only for entries to the country for those from certain countries.

3 minutes ago, CharlieH said:

Any extension will only be give for the remaining period of the passport. So 3 months in your case . I suggest you get s new passport and apply for it 4-5 months BEFORE given the current passport situation. (If UK)

Thanks for the information (subsequently confirmed by Ubonjoe)
Yes, it is a British passport, unfortunately.

My next question, on another forum will be about UK passport renewal.

3 minutes ago, ubonjoe said:

Then when you get a new passport you will have to apply for a new extension.

Gone are the days of getting the remaining portion of your "Year Extension" transferred into your new passport.

4 minutes ago, foreverlomsak said:

Gone are the days of getting the remaining portion of your "Year Extension" transferred into your new passport.

It has been gone since August of 2013.

8 minutes ago, mrjohn said:

My next question, on another forum will be about UK passport renewal

Ubonjoe posted useful links in the above thread. 

There is pinned information for UK renewal including forms in the UK FORUM

Looking on the bright side....... the good news is that if my new passport did not come through in time I would still be able to get my Visa extension while waiting for it.

Last time (10 years ago) it was a fairly simple process done by post.

2 minutes ago, CharlieH said:

There is pinned information for UK renewal including forms in the UK FORUM

Thanks, I'm currently trying to find a UK forum. Any pointers please?

1 minute ago, mrjohn said:

Thanks, I'm currently trying to find a UK forum. Any pointers please?

 

1 minute ago, mrjohn said:

Thanks, I'm currently trying to find a UK forum. Any pointers please?

The pinned topic he wrote about is here in the UK & Europe subforum of the Home Country Forum.

 

14 hours ago, mrjohn said:

Looking on the bright side....... the good news is that if my new passport did not come through in time I would still be able to get my Visa extension while waiting for it.

Last time (10 years ago) it was a fairly simple process done by post.

But just be aware that, as already stated, you would only receive an extension of 3 months max. If you still hadn't received your new passport by 6 January 2023, my advice to you would be to apply for a 60-day extension for the purposes of visiting your wife instead - and keep your fingers firmly crossed that those incompetent clowns at HMPO somehow managed to get your new passport to you via VFS by 6 March 2023 (or thereabouts)!

 

Sadly renewing UK passports from Thailand these days is not the relatively straightforward process it was 10 years ago. ☹️