@Paul *******
I renewed my last passport when I went home to Ireland for a holiday through the post method. I travelled back to Thailand using my still valid old passport and when my 90 day sign in was due I had to go to the Irish Embassy to get a verification letter for the new passport. It always struck me as a bit of a "rip off". Had to pay 1,000 Baht to the Irish Embassy to have my passport verified... that had been issued to me by the Irish Government?
PS. Often wondered, if I had produced my new passport when returning to Thailand (along with my old one for the stamps) at the airport and got it stamped, wouldn't that have been a verification in itself.