Update for those using Kanchanaburi IO and TM30 requirements:

I returned from abroad on the 10th and on the 11th reported to the IO in Kanchanaburi. Luckily I had my landlord with me, as they asked for him, but just looked at him and his ID - I already had his signature on the form. Quickly got a new TM30 slip, which surprised me as I had heard from another poster that they were fining for in country stays outwith the province, not just when returning from overseas. Having been to Hu Hin in April for a week I suspected their system would throw that up and fine me, but nothing happened even though the IO accessed the computer before giving me the new slip.

All good, I didn't raise any issue so went to the second office for a new 90 day slip. On receipt I asked the IO if a TM30 was required for returning home from another province and she said yes, the hotel will log your stays so we need to know when you return. I asked her, given that I have a 320Km round trip home to office if I could go to Sangkhlaburi office which is only an hour away. The answer was no, but she suggested I sign up for the online TM30 system set up for hotels and landlords. Again this is contrary to another poster, who was told they couldn't use it. However I am planning to register and give it a go.

My plan is therefore to go in person if returning from abroad with anew TM6, and to use the online system if coming back from a different province after a holiday.

Confused? I am.