Well, I'm a Malaysian now working in SG. I did not do a tax clearance nor close the tax account but I still submit my income tax return yearly (with zero income la).

My uncle left Malaysia, did not close his income tax account nor did he continue his filing. Years later when he return to KL for a visit, he was stopped by Kastam saying his passport is blacklisted. Apparently, LHDN assumes he is still working in Malaysia, and slap him with a RM20K tax bill. Pay or else he is not leaving Malaysia. Appeal will take months. He suck thumb and pay.