Me and my wife are at present in Thailand under a non-O retirement visa (90 days) obtained abroad.

 

I will go to the immigration for the permit of staying extension based on the letter of income that my Embassy is still issuing, and I suppose that I will get an additional year starting from the expiring date of my 90 days visa.

 

For my wife, that has no pension, we will ask a "dependent" extension based on my pension.

 

My question is : will the extension of permit for my wife start from the expiring of our 90 days visa or her one year permit will start the day when she will ask it ?

 

The logic would be to have the same expiring date, but I remember that, 4 or 5 years ago, in an identical situation, the Phuket immigration ( in the person of a very nervous and aggressive official) gave us two different expiring dates

Her extension based upon being you wife will start and end on the same day yours does.

If both your 90 day entries end on the same day it will be the same.