The IRS will start sending out monthly child tax credit payments next month to parents, grandparents and other guardians caring for children 17 and under. This is the centerpiece of President Biden’s anti-poverty agenda.

It would have been good if the agency had kept people like Willard McGruder in mind when they came up with their digital plans to reach some of the people who need the money the most — low-income Americans who earn too little to file an annual tax return.

McGruder is still waiting on the last two stimulus payments for the grandchildren in his care, a check worth $4,000 from the IRS that he should have received several months ago. The delay indicates the difficulties of getting pandemic relief money to the people most in need, and it’s not clear whether the IRS has overcome that obstacle with its new online tool, which works on desktops and laptops but is not mobile-friendly.

The payments starting in July were approved under the American Rescue Plan, which included a measure expanding the child tax credit for the 2021 tax year to a fully refundable $3,600 for children 5 and younger and $3,000 for those ages 6 to 17.

McGruder would be eligible for monthly payments of $300 for 2-year-old Rahine and $250 for his other grandson, Keshawn, 8. The retiree said he needs a bedroom set for Keshawn. He’s trying to catch up on a utility bill.

“The money would be a help,” he said. “I’d be grateful.”

This week, the IRS launched an updated version of the online non-filer tool it used last year to help people claim stimulus payments. The tool is now enabled to help non-filers register for the advance child tax credit payments. It was developed in partnership with Intuit and is specifically designed to target families who don’t normally file tax returns.

Eligible families who already filed or plan to file 2019 or 2020 federal returns, ​or who used the non-filer tool last year, should not use this tool.

Instead, the IRS says, the tool was built to provide an easy way for eligible people who earn too little, and thus do not have to file an income-tax return, to give the agency the basic information required to issue the monthly advance child tax credit payments.

Except, the tool is anything but easy, said Jennifer Burdick, supervising attorney with Community Legal Services of Philadelphia, and Melanie Malherbe, a managing attorney at Greater Boston Legal Services.

Although they praised the IRS for developing the online non-filer tool, they argued that the portal probably won’t be accessible to many people who most need the monthly child tax credit payments. This is, after all, supposed to be the Biden administration’s big social-safety-net initiative — and is projected to cut child poverty in half.

“I am disappointed that the IRS did not learn any lessons from the problems with the non-filer’s portal last year,” Burdick said. “This portal is still not mobile-friendly. And I think that’s a huge access point. It’s still only in English.”

I asked Intuit whether the tool could be used on a mobile device.

“Users are able to register for the monthly Advance Child Tax Credit payments through their browser on their computer or mobile device,” the company said in an email.

But in an FAQ, the IRS explicitly said, “no” to using the non-filer tool on a phone. “We recommend using the product on a laptop or desktop computer instead,” the agency writes.

When setting up an account, people have to provide an email address. But many potential users don’t have one and thus are shut out of using the tool, Burdick and Malherbe pointed out.

“There is a digital divide,” Burdick said. “Many low-income people do not have access to laptops or Wi-Fi. Smartphones are the most pervasive way that people connect to the Internet. The whole point of this portal is to make filing as accessible as possible, so I’m a little bit baffled that this very large step wasn’t taken.”

Malherbe also worries that many people won’t be able to use the portal.

“The estimates of getting children out of poverty are premised on access,” Malherbe said. “The instructions on the portal are very densely and confusingly written. It’s the opposite of simple.”

Malherbe said many non-filers need direct human interaction with people who know enough to be able to translate the information about what the IRS requires.

“The chances of the IRS having done it well were probably slim, but this is even worse than I imagined,” she said.

Malherbe said her organization will probably end up helping people just file a return.

“On our end, that’s actually easier to do than using a tool like this,” she said. “It would be helpful if the IRS would acknowledge the resources needed to make this accessible.”

The challenges could result in significant delays for families receiving the monthly child tax credit payments, she said.

Nina Olson, who served as the independent national taxpayer advocate for 18 years, says she’s “profoundly” disappointed in the updated version of the non-filer portal.

“We know a lot about this population,” said Olson, now the executive director of the Center for Taxpayer Rights. “They don’t necessarily have laptops. They may be disabled. They may have functional literacy challenges. There has to be another way to assist these people with perhaps a phone-based system.”

In response to the criticism, the IRS said in an emailed statement: “The work on this was accelerated to make it available as quickly as possible leveraging pre-existing programming. However, we will work with our partner groups to help ensure there is wide access to this important new tool.”

In fairness to the IRS, sending monthly child tax credit payments is a heavy lift for an already beleaguered agency. Still, in this next step to assist an economically vulnerable population, the agency has to step up its game.