Which immigration office? Every immigration office is different.

@Heinz **********

not a temporary condition. The MFA created the DTV without any input from immigration. Immigration wants nothing to do with it.

@Álex *******

you'd have to leave Thailand without a re-entry permit and then either purchase a new 90-day non-O from a nearby Thai embassy or return as a tourist and convert to the 90 day non-O at your immigration office. If you're truly planning on Thailand for the long haul, you should do it. You can even time it to make your yearly extensions fall at the most convenient time for you (perhaps low season?).

Which consulate? There are 4 and they're all different.

That's generally only for people applying for visas or extensions in Thailand at an immigration office, and using a Thai bank to provide the statement to immigration. That's not an embassy requirement.

Does your embassy in Thailand provide income verification?

Once you enter Thailand, there are only two things you can use for the first 1-year extension.

1) Embassy verified income of 65,000 baht per month

2) Proof of 800,000 baht in your Thai bank account

If your embassy does not do income verification (many do not), then your ONLY option would be proof of 800,000 baht in your Thai bank account.

@Brenda ********

the requirements are very specific. Check your embassy for requirements on the coverage and which companies it must be from

The only way that it could be done is if your passport expires in February and you applied for an extension where the passport is not valid for the entire subsequent year. The extension granted would only last until the passport expiration date.

Otherwise your extensions will always be on the same date every year unless you started over from scratch.

Which embassy? What does the embassy's website say for their processing time?

Chiang Mai Visa Run is probably the most well known.