Hoping someone might be able to clarify my situation;

- I have a non immigrant O visa (multi entry)

- I took a trip to Hong Kong and flew back to Thailand on 8th March

- Applied at immigration office to renew my visa on 23rd March (received 30 days 'under consideration')

- Collected my new visa from immigration on 20th April

I'm trying to work out when my 90 days will be calculated from. I'm assuming it won't be the last date (20th April) as I wasn't technically reporting my address. I'm not sure which of the other dates it might be. Any help most appreciated.

You can not extend a 90 day non immigrant O visa for 30 days unless a medical condition or some such other out of the normal reason so suspect you are saying you applied for one year extension of stay for marriage and got a 30 day under review period? Your 90 day address report will be due 90 days from the day your applied for extension (submitted the TM.7 form).

This brings up another question. I also have non-imm O w/multi-entry, ten years now. Returned from trip to Manila on 28-May so would do 90-day rept on 27-June. But I will be doing my visa extension renewal on 24-June, before the 90-day report due. So now, do I still do the 90-day on the 27-June, or does the meter get reset?

The 90 days starts again when you entered the country on 28th May.

I don't think you have a Non Imm O Multi Entry Visa.

I think you have a 12 month extension of stay.