I just want to share my experience so that others can have a smoother transition than me.
I am at CW for the 3rd time trying to transfer my extension based on retirement to my new passport - and failed for the 3rd time.
Whilst back in UK during summer of 2021, I obtained a new passport as my old/current one would expire in June 2022 and my extension renewal is in April. Returned to Thailand November 2021, showed both passports, no problem.
Went to MTT 10 days ago to do 90 days (online was rejected, probably due to new passport, but never got old online to accept my application) with both passports. MTT advised that I need to get extension transferred to new passport.
Went to CW, where I was advised that I need to do 90 day report first. Returned to MTT where I was able to do 90 day report.
Second time at CW, and after having paperwork checked and getting ticket number for L counter, I was advised that I need letter from embassy re new passport.
Made appointment at embassy, who advised me that I did not need letter as I had used my new passport to enter Thailand and it had entry stamp in it. I was advised that embassy or passport agency letter is only required if you receive your new passport while still in the country.
Returned to CW today. Paperwork all checked, received ticket for L counter. When called, IO accepted that I did not require embassy letter, but that I did require my bank book with itemised statement from time of my existing extension. I had my online app on my phone, but not good enough. My bank is one of those no longer at CW. This requirement was never advised to me before, nor is it on the list of requirements on the form to complete that I was originally given.
It should also be noted that you cannot make appointment for transfer of extension based on retirement, only for work permit related visa extensions.
So, this is a cautionary tale for anyone else out there wanting to transfer visa extension.
I do have a question for the community as today was the 3rd time and it costs 1000+ baht round trip each time. As my extension is due in APRIL and I have no problem carrying 2 passports around with me, can I just wait and do everything the same day or do I need to transfer extension first at a prior visit?