In 2016, about 29 million people filed their returns and owed taxes. Many people just pay the balance when they file – online or by check.

But what if you can’t pay in one lump sum?

You’re not out of luck. Here are three options.

1. Borrow the money.

This is a great option if you have someone willing to loan you the money, especially with no interest.

2. Pay with a credit card.

You may think about using a credit card now and paying off the balance over time. After all, you’ll get the points. But with some credit card interest rates topping 20%, it’s worth doing some extra math.

3. Work with the IRS.

Not everyone knows that the IRS will work with taxpayers who owe. Here’s more about the options you may have.

Ask for a little more time

If you just need more time to get the money together, you can ask the IRS for an extension of up to 120 days to pay your entire tax bill. Penalties and interest will accrue until you pay the full tax bill.

Set up a payment plan

If paying your entire bill upfront isn’t an option, the IRS offers several types of alternatives – like monthly payment plans (called installment agreements ).

And the penalties and interest the IRS charges on your tax balance may not be as high as you think.

Here’s why.

As of January 2018, the IRS charges a 4% interest rate on unpaid back taxes. The penalty for not paying (called the failure to pay penalty ) is ½ percent per month, maxing out at 25% of the amount you owe for each tax year with a balance. In short, the annual cost would be 10% of what you owe (4% interest rate, plus 6% total penalty for the year).

But if you get into a payment plan with the IRS, you can lower your costs. The IRS will cut your failure to pay penalty in half – to 0.25% per month. This lowers your annual cost to about 7%.

The IRS offers several types of installment agreements, and even has options for people in hardship situations. Learn how to set up an agreement with the IRS to pay your taxes.

What not to do: Ignore it

Do the math if you owe taxes and can’t pay right away. You’ll need to decide what’s best for your situation.

But remember: The one thing not to do is ignore it and hope the issue goes away. If you don’t make arrangements with the IRS on your tax bill, the failure to pay penalty rate can double — to 1% per month when the IRS starts collection proceedings against you (with actions like liens and levies ).

The moral of the story: File on time and work out an arrangement with the IRS for your outstanding tax balance . The sooner you do it, the less you’ll pay in the end.