(NewsNation) — This year’s April 15 tax deadline has come and gone. If you haven’t filed yet, what penalties could you face?

The federal government will assess a monthly penalty of 5% on the amount of taxes owed, not to exceed 25% of the sum, the IRS says. Someone who owes $5,000 in taxes, for example, will get fined $250 per month.

That’s on top of the taxes owed plus interest.

For people who can’t pay up, the smart play was to request an extension to stay in the good graces of the IRS rather than ignoring the problem. However, if you haven’t already filed an extension, you might be out of luck.

If you needed more time to file your taxes, you could’ve requested an extension, but you needed to do so by April 15. That would’ve given you an extra six months, until October 15, to file without penalties.

People who are granted an extension will generally pay smaller penalties and can even work out a payment plan, according to tax software provider TurboTax.

The IRS generally issues refunds within 21 days for taxpayers who file electronically and choose direct deposit. Paper returns take longer.