What are the TM28 and TM30 requirements for temporary stays at a different residence in Thailand?

The TM28 form is required if you temporarily change your residence, such as staying at your wife's parents' house. Since you are leaving one residence to temporarily stay at another, you should inform the immigration office using the TM30. Although the requirement usually lies with the property owner (your wife, in this case), it is advisable that she completes the TM30 form ahead of your stay, ideally within 24 hours of your arrival at her parents' house. Upon returning to your home, no further action is needed unless you have a change in your residence again.