I had to get a new passport in May 2021. The original visa sticker stays in the old passport but a few stamps are added to the new one. I travelled out of the country first time since in May this year. I was pulled aside and asked extra questions by IO but not sure if in relation to old PP or not.

 

I have not needed old PP in more than 3 years since renewed but did keep in just in case. I have heard that some countries keep your old PP when you get a new one.

 

As far as carrying PP all the same I never do as not needed. Even when I air travel within Thailand I carry PP but don't show it I use my Thai DL and never been asked for PP.

I used to travel for work a lot and filled up passports frequently. For VISAs to other countries, hand over both the old and the new passport to Immigration when entering. Show them the VISA page. Immigration doesn't care...even  entering China.

 

For your Thailand VISA, take both passports to Immigration and they will transfer the stamp for you.

8 hours ago, scoutman360 said:

For your Thailand VISA, take both passports to Immigration and they will transfer the stamp for you.

 

Incorrect, no they won't. VISAS are not transferred, only extensions of stay are.

20 minutes ago, AdeBeaudu said:

When you get a new passport, your visas usually don’t automatically transfer over.

Won't include rest of your post.

In the main incorrect.

This thread is Thailand specific.

Visas are not transfered. 

For folk living in Thailand on eg extensions from a non O-A, non O etc....the information noting details of the visa is transferred.

Have that done at Thai immigration office along with reentry permit (if have one) 

 

Multi enter visa is different. 

They are not transfered and if travel internationally then required to present both pp. 

 

Any valid visa, reentry permit etc remains valid in old pp even when that pp is cancelled. 

Note: for others. Stamps are transfered where they are issued. I obtained new pp recently at CW and they cannot transfer reentry permit as I always obtain permit at airport.

Travel to Vietnam often and as result I need to travel with both passports.