For a number of years I had a "B" visa and work permit.

Last year I decided to "retire".

I returned the work permit and visited my local immigration office to advise tehm that it was now my intention of staying in Thailand based on my age (over 50) and pension monies.

An 1 year extension of stay was stamped into my passport.

All well so far.

I have now been tempted back into the work force and seek to apply for a work permit.

Do I need to leave Thailand and apply for a "B" visa at a Thai consulate or embassy in a neighboring country or can I reverse the process of last year by once again visiting my local immigration office?

What does the panel think?

You cannot work on an extension of stay based on retirement, so you might need to go abroad for a new visa. But try it, it will depend on the officer.

What you first need to do is apply for the work permit. Since you don't have the right permission to stay, you will get a WP3 form. With the wp3 form (that signals that you will get a work permit once you have the right permission to stay) you can try to get an extension of stay based on employment. If they refuse to give you an extension of stay based on employment, you will need to go broad and take the WP3 form with you. Consulates in the region will want to see that one, as several other documents form your employer.

Many thanks for your reply Mario