Even the smallest issue with your Earned Income Tax Credit (EITC) claim gives the IRS a reason to deny your claim or delay your refund. And we single moms have so much going on all the time that it’s easy to overlook things and make mistakes.

But one of the most common things that block our tax refunds: Our exes. That’s right, our exes can hang up our EITC claims…but we wouldn’t know until we get that nerve-wracking letter from the IRS.

The average EITC last year was $2,455


And while that can be the biggest EITC-related problem to solve, there are other issues that can slow down tax refunds and kick back EITC claims.

EITC Problem #1: Your ex also claimed the kids on his tax return

The EITC can mean a lot more money in your pocket – and your ex may want that cash. When both of you claim the kids – or the EITC credit – that’s a major red flag for the IRS. They will go after both of your tax returns, even if yours is the legit claim.

The solution:

Prove that the kids lived with you for more than half of the tax year.

EITC Problem #2: A Social Security mismatch – common when there’s a name change

There’s a lot of paperwork involved in divorces, and sometimes things don’t get filed properly. If you’ve changed your last name (or your kids’ last names) after a divorce, make sure Social Security knows about it. If not, and your name and number (or the kids’) don’t match up, your tax return will get flagged for audit.

The solution:

If you haven’t changed your name (or your kids’ names) with Social Security, use the name they have listed on your tax return. After you get your refund, make the necessary changes so you don’t get hung up next year, too. Here’s how to change your name with Social Security.

EITC Problem #3: Using the wrong filing status

A lot of single moms get hung up here. The IRS rule is your filing status for tax purposes is based on your marital status on December 31 of the tax year (so December 31, 2016 for tax year 2016, which you file in 2017). If you’re legally married on December 31, you can’t file as Single or Head of Household.

The exception:

If you have a legal formal separation agreement as of December 31, you can use the Single or HOH filing status.

EITC Problem #4: Your child doesn’t qualify as a “qualifying child”

If your child didn’t live with you for more than half the year, or turned 19 by the end of the tax year (or turned 24 for full-time students), he or she doesn’t count as a qualifying child for the EITC. Fully, permanently disabled children qualify no matter how old they are.

The solution:

You may still qualify for the EITC even if your child doesn’t. And if you have more than one child, your other children could still qualify. The income cut-off will be lower, and the maximum credit will be smaller – but if you can reap any portion of the EITC benefit, go for it.

Knowing the most common problems can help you avoid them – and help you get your full refund, including your EITC, as quickly as possible.