Final answer:
Taxpayers can generally change their filing status after the due date if amendments are due to specific changes in personal circumstances or errors on the original return, using Form 1040X within a specified time frame.
Step-by-step explanation:
The rules for changing filing status after the due date of the return allow for corrections under specific circumstances. In general, once you have filed your tax return, you are not allowed to change your filing status from joint to separate after the due date; however, there may be exceptions based on changes in personal circumstances such as marriage annulment or changes involving dependents.
If a taxpayer discovers an error on their return, they can file an amended return using Form 1040X to correct the filing status but this must be done within three years from the date the original return was filed or within two years from the time the tax was paid, whichever is later.