I am correct? As the Thai law seems not to make a difference between a tourist on holiday or an non-immigrant living here I was wondering. A tourists arrives at the airport and fills in the addresses of his hotel in Bangkok at the arrival card. So he has informed the immigration about his stay (TM28?). When checking in at the hotel the hotel manager will report to immigration (TM30?). Everything OK. After 5 days he goes to Kanchanaburi and again at checking in at his new hotel the manager will report him to immigration (TM30?). But actually he should also visit the immigration to file a TM28?
TLDR : Answer Summary
The discussion clarifies that when a tourist in Thailand moves to a different hotel, the only requirement is for the hotel manager to file a TM30 report with immigration. The necessity of filing a TM28 is not required for tourists in this context, as clarified by commenters who point out the focus is on TM30 compliance.