If you didn’t get your August advance child tax credit in your bank account today, you’re not alone. Due to “an issue,” a percentage—less than 15%—of folks who got their payment by direct deposit in July will be mailed paper checks for the August payment, according to an Internal Revenue Service news release. Another way to put it: More than 4 million families will have to wait for a paper check. That could be at the end of August. “For those receiving their payments by paper check, be sure to allow extra time for delivery by mail through the end of August,” the IRS says.

The first batch of advance monthly payments sent out in July worth roughly $15 billion reached about 35 million families. About 86% (30 million families) got their July payments by direct deposit. That would work out to 4.5 million folks stuck waiting for their August payments. The IRS says it expects to have a fix before September, so for those affected, September payments will resume by direct deposit.

Most families will see the August direct deposit payments in their accounts starting today, August 13. Subsequent payment dates are: September 15, October 15, November 15 and December 15.

Normally you get the Child Tax Credit when you file your tax return (you’d get the 2021 credit in the spring of 2022 when you file your 2021 tax return). But the American Rescue Act both increased the tax credit dollar amount and included a provision to make half of the credit available as advance payments on a monthly basis starting July 15—for 2021.

The expanded credit provides parents with a $3,000 credit ($250/month) for every child age 6 to 17, and $3,600 ($300/month) for every child under age 6 (that’s up from $2,000 per dependent child up to age 16). Individuals earning up to $75,000 a year, heads of household up to $112,500 a year, and joint filers up to $150,000 a year are eligible to receive the full amount of the enhanced credit. The credit is nonrefundable, meaning you don’t need income to receive it (normally to take advantage of a tax credit you need income that it would offset). Earn too much to get the enhanced credit? The advance payments apply to the basic $2,000/year child tax credit, too. That phases out at $440,000 of income for a couple.

Didn’t get a July payment? Families who did not get a July payment and are getting their first monthly payment in August will still receive their total advance payment for the year. This means that the total payment will be spread over five months, rather than six, making each monthly payment larger.

Some families will get two August payments. In another fix, the IRS is correcting an issue regarding payments for families where the parent(s) have an Individual Taxpayer Identification Number and the qualifying children have a Social Security number. For these families who didn’t not get a July payment, they should get a monthly payment in August, which includes a portion of the missed July payment. They should get the remainder of the July payment in late August.

Keep in mind—the advance child tax credit is an advance, meaning you could get a smaller refund or owe more when you file your 2021 taxes next spring. To decline advance payments or to update your bank account information, go directly to the IRS Child Tax Credit Update Portal or access it from the IRS’ Advanced Child Tax Credit Payments In 2021 page.