Congress expanded the child tax credit earlier this year, and the IRS will on July 15 make its first batch of monthly payments to about 39 million families with children.

Tens of millions of households will receive up to $250 a month per child between age 6 and 17 and up to $300 per child under age 6, based on their ages at the end of 2021. The payments will be made on the 15th of every month, unless that date falls on a holiday or weekend, the Treasury Department said Monday. Unless Congress extends the program, it will expire at the end of December.

The IRS will send taxpayers notices about the size of their child credits and information at the end of the year they can use to reconcile the credit amounts on their 2021 tax returns. Households that have already filed their 2020 tax returns don’t need to do anything else to start receiving the payments in July. If the IRS doesn’t have a 2020 tax return, it can use 2019 data. About 80% of recipients will get the money through direct deposit, with the rest getting checks or debit cards.

The IRS will be setting up an online portal where people can opt out of receiving the monthly payments (instead claiming the credit on their tax returns) in addition to a portal where people who don’t typically file tax returns can give the IRS their information to start getting the money. The agency will soon also post a list of frequently asked questions about the credit.