Example - Krabi Immigration is NOT hard core about a lot of things but they do expect people to report just after they arrive in Thailand for Visas such as the non Imm O-A.. My neighbor is on an O-A visa and I went with her.. They explained the local policy - put her details in the computer system and gave her a slip of paper with her 90 day report date.. Nothing punative just matter of fact and the I/O was very professional about it
Depending on where you reside in Thailand and the Immigration office you report to - consider this... you may be required to report to Immigration within 24 hours of your arrival in Thailand. Also the best thing to do is report to Thai Immigration asap anyway.. They will register you as being here, they may substantiate your address here and set your 90 day report date (which should be 90 days from the date of your arrival in Thailand - when you were stamped in