What is the effect of not having a valid ID number by the original return’s due date?

The option that states it renders the taxpayer ineligible for certain credits is correct because having a valid ID number, such as a Social Security Number (SSN) or Individual Taxpayer Identification Number (ITIN), is essential for claiming various tax credits. These credits often require valid identification to ensure that they are applied to the correct taxpayer. If a taxpayer does not provide a valid ID number by the original return’s due date, it creates a barrier to claiming specific benefits that rely on proper identification, such as the Earned Income Tax Credit or Child Tax Credit. This ensures that only eligible taxpayers can receive these credits based on identifiable information, maintaining integrity in the tax system.

Other options do not accurately reflect the consequences of not having a valid ID number. For instance, the suggestion that taxpayers can refile their return for a fee isn't generally applicable to missing ID numbers; instead, there are specific procedures that taxpayers must follow. Additionally, while a lack of valid ID may affect eligibility for certain credits, it does not imply that all credits will be lost, as some might still be accessible. Finally, stating that there is no effect on filing status is misleading, as the absence of a valid ID number directly impacts the ability to claim certain credits.