If you file your return or pay your taxes late, you can suffer a variety of consequences. This is true whether you have a refund coming or owe taxes.
Delay in receiving your refund
You will not get your refund until you file your tax return.
Penalties and interest
The IRS may charge you interest and penalties.
The IRS may file a return on your behalf
This is called a Substitute for Return (SFR). Because the IRS may not have complete information about your situation, they may overstate your tax liability. This could mean you’d owe more taxes than if you filed your own return, or you will receive less of a refund than if you had filed your own return.
When you file a return or the IRS files a substitute return that shows a balance due, the IRS will try to collect that amount. Depending on your situation, the IRS may file a lien that attaches to your property or rights to property or place a levy on your bank account, wages, or other sources of income.
Another possible consequence of not filing your own return is that someone else might use your Social Security number and file a false return, stealing your identity. If this happens, when you do file, your return and any refund will be delayed while the IRS determines which return is correct.
“Losing” your refund
You must file your return within a specified period to receive a refund. In general, you can “lose” your refund if you don’t file within the statute of limitation.
In general, you have three years from the due date to file and ask for your refund. If you don’t file within that time, you generally won’t get your refund.