@Robert ***********
The requirements can vary some between the different immigrations. This is the requirement for a Extension of Stay at Jomtien immigration;
TM.7 form for applying
*Passport
*Copy photo page passport
*Copy latest stamp in passport
*Copy visa or extension in passport
*Copy TM.6 if you have. (Suspended airport at date)
*Receipt TM.30
*Lease contract or proof of home
*Pass-photo
*Bank statement or confirmation from your embassy
*1900 thb cash
You don’t need both TM.30 registration and lease contract.