Currently I am on a non-O spouse visa with a work permit through my business in Bkk. The visa is not is not issued in Bkk, it's in a neighboring province where I live. This year I want to switch to non-B. Is it likely that immigration will not allow this? Would the normal procedure be to visit my local imm office and ask them for a list of requirements? Thanks in advance.

You apparently have a extension of stay (it is not a visa) based upon marriage to a Thai.

You cannot change to a non-b entry without leaving the country. You can change the reason for your extension from marriage to working for a company.

You may have to apply for the extension based upon working at Chaeng Wattana immigration.

You should check with your local office about doing it there.

A general list of required documents for a extension based upon working is number one here.

https://bangkok.immigration.go.th/en/non-quota-immigrant-visa/

I was on an  extension of stay (based on marriage) with a non-O visa before, and wanted to switch the reason to "working", as we were about to divorce the next year. In theory it's possible, but eventually I had to leave the country to do a non-B. The problem was one document from the BOI had expired, and they were not not willing to update it until next year, or provide another document to avoid this. 

 

So it's possible, but since multiple agencies are involved (labor ministry ,immigration, and maybe others) this may not always work out.

3 hours ago, Smithson said:

Currently I am on a non-O spouse visa with a work permit through my business in Bkk. The visa is not is not issued in Bkk, it's in a neighboring province where I live. This year I want to switch to non-B.

I used to have a non-B with a work permit through my own company. It was the chief of the local immigration office who said to my wife when we were renewing one year, why are we making it difficult for ourselves having a non-B when it be easier/better to have a non-O; we changed to non-O next extension time. So why do you want to switch from non-O to non-B - what's the benefit? 

 

See the attachment about working in different locations on your work permit.

 

Thailands New Work Permit Law_NARITLAW.pdf

1 hour ago, SymS said:

I was on an  extension of stay (based on marriage) with a non-O visa before, and wanted to switch the reason to "working", as we were about to divorce the next year. In theory it's possible, but eventually I had to leave the country to do a non-B. The problem was one document from the BOI had expired, and they were not not willing to update it until next year, or provide another document to avoid this. 

 

So it's possible, but since multiple agencies are involved (labor ministry ,immigration, and maybe others) this may not always work out.

Did you have a WP at the time?

18 hours ago, Smithson said:

Did you have a WP at the time?

Yes.