Resident in Chiang Mai ( And I believe some other provinces) and going to another province where your hotel etc reports your stay you are obliged to inform your landlord to file a new TM30 on your behalf when you return to Chiang Mai to avoid problems when submitting future 90 day reports.
Now here is a twist. Submitted 90 day reports online (Wife and I) only to get both applications rejected due to:
"The last declaration of accommodation (TM30) is not Chiang Mai."
I was at a loss, had not been anywhere since my last 90 day report in early February. Only solution was a trip to immigration which I rarely do, took both passports. Expecting some sort of hassle went to the info desk and explained the situation.
The young officer took the passports and a couple of minutes later came back with a senior lady officer who clearly explained what had happened.
My wife had gone down to Bangkok in March for two days and her hotel had reported accordingly. So her 90 day application was rejected because the TM30 had not been updated, fair enough, but mine had also been rejected!
It turns out that as my wife's extension of stay is as a dependent and the effect of the hotel reporting her stay effectively also reported my absence despite not even having travelled! I repeated what the officer had said and she confirmed again this is what had happened.
How is that for a weird one?
Landlord has submitted new TM30, we will do 90 days later.