I have had a new passport within the last 12 months but my arrival card has my old passport number on it, I have done a few 90 day reports since(in person) no problems, if they checked the arrival card and noticed it showes my old passport number would there be a problem? I have not left the country since my entry in Nov 2018. I am on a Retirement extension since 2009.

Hope I have explained so it is understandable.

No...

My very old TM6 card still has my old passport number on it and I have never been questioned about it since I got a new passport back in 2013.

3 hours ago, Badrabbit said:

if they checked the arrival card and noticed it showes my old passport number would there be a problem?

 

If it had been an issue with your office, they would presumably have raised it with you when transferring existing stamps from your old to new passports (assuming, of course, that you have already been through this process).

 

As well your TM6 card, the point which you have raised also appears to be germane to the TM30 receipt notification which you presumably also have stapled in your passport. I take it that, as part of the stamps transfer process, your office did not request a fresh TM30 for you solely on account of your new passport number?

https://www.officemate.co.th/en/office-supplies/erasers-correction-products/correction-pen-and-correction-fluid

When Immigration updated my new passport recently the TM6 form remained in my old passport.

 

Should I move this to my new passport, or OK just to leave in the old passport with the update stamps presumably having all the info that might be needed when next exiting Thailand? 

17 minutes ago, dabhand said:

Should I move this to my new passport

Yes

It's such a silly thing to have.  Wish they would have got rid of it like they were talking about a couple of years ago.

4 hours ago, dabhand said:

When Immigration updated my new passport recently the TM6 form remained in my old passport.

 

Should I move this to my new passport, or OK just to leave in the old passport with the update stamps presumably having all the info that might be needed when next exiting Thailand? 

If it was me, i would leave it in the old PP, but ensure that I had both PPs ready to hand when I left. That way the IO can see exactly what has occurred and can still take the TM6 as (s)he wishes.  It would save you having to attempt to explain to the IO what has occurred.

as for me ... i carried my old pp for a while then everything got tranfered to new  .. 

11 hours ago, Badrabbit said:

I have had a new passport within the last 12 months but my arrival card has my old passport number on it, I have done a few 90 day reports since(in person) no problems, if they checked the arrival card and noticed it showes my old passport number would there be a problem?

No problem, and I talk from experience with old pasport number on departure card...????

 

Edit: If you got your entry visa etc. transferred to your new passport, the old passport number will be mentioned there.

6 hours ago, VBF said:

If it was me, i would leave it in the old PP, but ensure that I had both PPs ready to hand when I left. That way the IO can see exactly what has occurred and can still take the TM6 as (s)he wishes.  It would save you having to attempt to explain to the IO what has occurred.

Yes, that sounds like a plan.

 

I was a bit surprised to see that the TM6 had not been stapled to the new passport, as I was expecting. Thought possibly by oversight but, as another poster mentioned, the details would have been entered into the new passport anyway,