(NEXSTAR)  — The IRS says 88 percent of U.S. families with children will be automatically enrolled to receive the new monthly child tax credit payments starting next month. But as with many tax breaks, many parents may prefer one big payout at filing time to the gradual increase through the year. The Internal Revenue Service says that will be an option with the beefed-up child tax credit, but it’s up to taxpayers to delay the payment.

The American Rescue Plan passed earlier this year, increasing the existing maximum child tax credit to $3,600 for children under 6 and $3,000 per kid for children between 6 and 17. It also set up a framework to prepay a portion of those funds over the final six months of 2021 through the IRS. According to the feds, roughly 39 million households will begin receiving checks on or after July 15th, “without any further action required.”

“Households covering more than 65 million children will receive the monthly CTC payments through direct deposit, paper check, or debit cards,” the IRS wrote in a press release last month.

The increased payments will phase out for higher income earners, including parents filing jointly who earn over $150,000.

Child Tax Credit Payment Calculator

Use the calculator below to estimate how much you might receive in child tax credit periodic payments beginning in July, 2021

If you’d like to keep taking the full credit on your taxes next spring, as you may have with the smaller payout in previous years, you’ll have a small window of time to take action. The IRS is expected to make new tools available this month to allow taxpayers to change information about filing status, the number of qualified children, and changes to their income, as well as the payout preference.

CNET reports the agency will launch two portals by July 1st. The primary portal will be used to opt-out of monthly payments and the second will be for families that don’t typically file taxes, allowing them to make the government aware of their dependents.

The exact date of launch of these tools is not yet known, and the IRS website simply says, “More details on how to take these steps will be announced soon.”

The first round of check distribution is now just six weeks out, leaving the IRS a small window of time to absorb the crush of delayed 2020 taxes, launch these new portals and begin distributing millions of new monthly checks.

The advance payments run from July through December, and cover up to 50% of the available credit, meaning that taxpayers who do take the monthly checks will still see half of their benefit at tax-filing time.