The Internal Revenue Service plans to send electronic payments as soon as late next week to millions of Americans as part of the $2 trillion coronavirus law, a week sooner than expected, according to a plan circulated internally on Thursday.

However, $30 million in paper checks for millions of other Americans won’t start being sent out until April 24, as the government lacks their banking information. And some of those checks won’t reach people until September, the document shows, underscoring the reality that many Americans could have to wait five months to receive their checks.

The speed with which the money is disbursed will depend largely on people’s method of filing taxes. Electronic payments can be distributed quickly, whereas the IRS must print paper checks and mail them separately. About eight in 10 taxpayers have signed up for direct deposit payments for their past tax refunds, a number that has grown in recent years.

At a White House press briefing Thursday, Treasury Secretary Steven Mnuchin said these eligible Americans will receive the money within two weeks.

“If we have your [bank] information you’ll get it within two weeks,” Mnuchin said. “Social Security, you’ll get it very quickly after that. If we don’t have your information you’ll have a simple web portal, we’ll upload it. If we don’t have that, we’ll send you checks in the mail.”

He added that “In this environment, we don’t want to send checks and we want to put money directly into [taxpayers’] accounts.”

Patricia McLaughlin, a spokeswoman for the Treasury Department, the IRS’s parent agency, said in an email that “the overwhelming majority of eligible Americans” will receive stimulus payments within the next three weeks.

She said that Treasury expects 50 million to 70 million Americans to receive checks through direct deposit by April 15, offering a slightly different assessment than the IRS draft plan.

Taxpayers who haven’t provided direct deposit information on their 2018 or 2019 tax returns will be able to enter it in a portal the IRS is setting up to speed up receipt of their checks, McLaughlin said.

The IRS plan would distribute paper checks to the lowest-income Americans first, prioritizing payments for individual taxpayers with incomes of $10,000 or less on April 24.

Checks for earners of $20,000 or less would be in the mail May 1, followed by those with incomes of $30,000 on May 8, $40,000 on May 15, and continuing in income increments of $10,000 each week, according to the plan. The IRS plans to issue about 5 million checks each week.

Stimulus checks would be issued on Sept. 4 to joint taxpayers earning $198,000, the maximum allowed under the stimulus. All others would be sent on Sept. 11, in most cases because the IRS did not have prior tax information for them and they need to apply for the checks.

The tax agency is racing to set up payment systems as millions of Americans have been forced out of the labor force by the pandemic, with jobless claims soaring to a staggering 6.6 million last week.

The plan is to generate electronic checks on April 9, according to the payment schedule reviewed by The Washington Post. Depending on how quickly banks process the payments, they would be deposited by April 14 at the latest.

“If we know where to put the money, we’re going to press the button and put it there next week,” said an IRS official who was not authorized to speak publicly.

American adults who earned less than $75,000 will receive a $1,200 payment, and an additional $500 per child. The payment will be phased out for Americans who receive more than that, and adults that earned more than $99,000 will not receive the benefit, under the law.

About 145 million Americans are eligible for stimulus checks, depending on their income. Mnuchin had said he expected most Americans to get their payments by April 17. The IRS still has not said publicly how long it would take the agency to issue paper checks, or how it plans to decide who should get them first.

Another 64 million Americans receiving Social Security and disability income will also receive checks, many of them electronically, after the Treasury Department announced Wednesday that they can get payments even if they typically do not file a tax return.

Most taxpayers will not have to file a separate claim with the IRS to receive their checks. The new law directs the Treasury to look at Americans’ 2019 or 2018 tax returns to determine if they are eligible for a payment.

The agency had strongly considered spacing payments out based on $25,000 income brackets but concluded in recent days that it needed to send the checks in smaller batches because its networks do not have the bandwidth to issue so many checks in one week, the IRS official said. A slower ramp seemed more manageable, the official said.