The Internal Revenue Service is reminding people that the extension deadline will end on Oct. 15—and those who haven’t paid by that date could face penalties. Late filers face fees equal to 5% of their unpaid tax bill. That’s charged for each month or part of a month the return is late.

On average, approximately 7% of taxpayers seek a six-month extension to get their finances in order or focus on more pressing issues. In 2019, some 12 million took advantage of the extra time.

People who are due a refund don’t face penalties, but won’t see that money until they file. And if they wait too long, the IRS says, they could risk losing the refund altogether.

There are some exceptions to the deadline. Members of the military and others serving in a combat zone have 180 days after they leave the area to file returns and pay taxes. And taxpayers in federally declared disaster areas may be granted more time as well.

The deadline is also important for people who missed out on one or both of the first two stimulus payments or didn’t get the full amount. The IRS urges people to file a 2020 tax return or use the Child Tax Credit Non-Filer Sign-Up Tool to provide necessary information to send the payments. It will also use that information to evaluate eligibility for the $1,400 third-round stimulus payments when the 2020 return is processed.