Just got notice from the school in Bangkok my kids attend that immigration has sent the following communication, hope it may be of use:

Recently, the Thai government made a few key personnel changes within the Immigration Bureau of the Ministry of Foreign Affairs. Corresponding to this, they also provided a reminder of several legally required processes for foreign nationals. One such process, enacted in 1979 but not fully enforced, requires home owners, landlords and hotels to notify immigration authorities within 24 hours any time a foreign national who is staying at their residence arrives in the country.

Although the Immigration Bureau has been lenient with members of the community in respect to this requirement, please be aware that it may be enforced more strictly in the future. We recommend reviewing the information below and, if necessary, forwarding it to the relevant individuals to ensure that you are in compliance.

Following is the link for the requirement: