Do I need long-term accommodation to qualify for a Certificate of Residence in Chiang Mai?

Not sure on the rules in Chiang Mai, but in Phuket (as an example) you can get a certificate of residency on any visa entry, long or short stay accommodation. They just require that a TM30 has been filed. Your landlord “should” have filed one within 24 hours of your arrival. However many don’t. Ask them if they did and get a screen print of the filing. Take that along with a copy of your passport data page, entry stamp and a photo and you may be good to go for the cert.

If they haven’t filed a tm30 then that where things get tricky because you’ll need a number of documents, including copies of your landlords ID, house registration, a power of attorney form and rental contract to file it yourself.

Where ever you stay, they need to submit a tm30. Take the tm30 receipt and your passport to immigration before 11:30am. No minimum stay required, 1 nught is fine, but they mail the COR to the address you use on thebtm30.