Do-it-yourself online tax preparation services promise expert advice and “guarantee” to maximize your refund. But can they live up to these claims?

Consumer Reports reviewed H&R Block Deluxe, TaxAct Online Deluxe+, TaxSlayer Premium and TurboTax Deluxe, and found at least one glitch in each of the services, including two that could lead to a missed tax break, reducing the allowed refund from the IRS.

“These problems included outdated information, incomplete advice, and program designs that — in a couple of instances — could affect a taxpayer’s bottom line,” writes Tobie Stanger, a Consumer Reports senior editor.

Stanger “test drove” the four popular tax-prep services (their online versions and mobile apps) using her own personal tax information. She also looked through the tax-information databases and posed questions to each service’s tax experts, as any other customers might do.

“The new tax law [Tax Cuts and Jobs Act of 2017] was reflected in all of the products, but in a few instances, they were not fully updated, or they were not designed quite as well as they could have been, which could cause some mistakes in some situations,” Stanger told NBC News BETTER.

Stanger found that some of the programs were “not very intuitive” and did not always lead her to the correct answer.

“In a couple of cases, that meant that a consumer might miss a tax break, and in one instance, we found they might get a tax break that maybe they weren't really eligible to get,” she said.

Because of the problems encountered, Consumer Reports decided not to endorse any of the products tested without some reservation.

“These products are reasonable for simple returns where you don't have a lot of complex issues related to dependents or a small business,” Stanger said. “If you have a more complex situation — especially if you have your own business — using a tax professional may be a better option.”

COMPANIES RESPOND

NBC News BETTER contacted H&R Block, TaxAct, TaxSlayer and TurboTax. All four companies said their products enable taxpayers to prepare an accurate tax return on their own.

“Creating an accurate and easy-to-use product for our customers is our top priority,” said Molly Richardson, director of strategic communications for TaxSlayer. In her email, Richardson went on to say that the problems uncovered by Consumer Reports, including outdated content, were corrected within 24 hours of being contacted by Stanger.

TaxAct disputed Consumer Report’s findings and said its Answer Center provided accurate guidance and information related to tax reform changes to “ensure all calculations are correct … and every deduction or credit change is included.”

“Like every tax season, our goal is to help our customers navigate the tax code with confidence, which includes all of the tax reform changes that went into effect in 2018,” TaxAct public relations wrote in its email. “We offer explicit guidance on several tax reform changes that impact the majority of our customers directly on the screen as they are inputting their information.”

TurboTax also challenged Consumer Reports' assertion that some of the information provided was not “entirely right.” Lisa Greene-Lewis, a CPA and TurboTax tax expert, said the answers given by its AnswerXchange were correct. “TurboTax is a trusted resource with over 30 years in the tax business and we have tax expertise, plus technology, and tools to make sure customers’ taxes are done right,” she wrote in an email.”

Greene-Lewis also disputed Consumer Reports' suggestion that people with complicated returns should see a tax pro. Customers can connect via one-way video to the company’s tax experts, credentialed CPAs or Enrolled Agents, who can answer questions that deal with complicated issues, such as rental property, life changes and side gigs, she wrote.

H&R Block did not respond directly to Consumer Reports' assertion that an H&R Block rep contacted through chat gave their reporter inaccurate information. In its written response to NBC News BETTER, the company’s public relations department highlighted the company’s various online products that offer various options for personal advice and assistance. “What’s important is that consumers get the care and expertise they need during tax season,” the emailed statement said.

CONSUMER REPORTS’ REVIEW

DIY tax-prep software is a popular option for many taxpayers. With that in mind, Consumer Reports offers these observations about the four online programs it tested.

H&R Block Deluxe is good for simple returns. Its guided tax-prep experience offers generally clear tax-law explanations and includes useful tools. It’s “a reasonable choice for simple returns — say, you rent and have one or more W-2s.”

is good for simple returns. Its guided tax-prep experience offers generally clear tax-law explanations and includes useful tools. It’s “a reasonable choice for simple returns — say, you rent and have one or more W-2s.” TaxAct Online Deluxe+ is relatively inexpensive. Once you begin using it, the price won’t change. “It may be suitable if you know what you’re doing. But you may not get through to a tax pro when you need help, from our experience."

is relatively inexpensive. Once you begin using it, the price won’t change. “It may be suitable if you know what you’re doing. But you may not get through to a tax pro when you need help, from our experience." TaxSlayer Premium gives fast answers from humans. “If you aren’t put off by a bare-bones user experience,” it provided “prompt, direct answers to our tax questions through chat, email, and phone, though not all were nuanced enough to completely rely on.”

gives fast answers from humans. “If you aren’t put off by a bare-bones user experience,” it provided “prompt, direct answers to our tax questions through chat, email, and phone, though not all were nuanced enough to completely rely on.” TurboTax Deluxe is user-friendly. It clearly outlined how the new tax law affects an individual user. “Assuming you don’t have complex questions, you can probably use this successfully, if you have wage income, a mortgage, and dependents.”

A full review with more on what Consumer Reports found is posted on ConsumerReports.org.

A FEW HELPFUL TIPS

Stanger offers a few tips for anyone who’s going to use one of these online tax preparation services:

If you are uncertain about a tax question or simply want to double-check an answer you get, check the IRS website. The Interactive Tax Assistant page has answers to dozens of questions.

If this is the first time using this service, use the program’s import function whenever possible to transfer data from W-2s and other forms, as well as last year’s tax return. This will save you time and help ensure accuracy.

You can’t rush it. Take the time to read everything carefully, click on the various definitions that are offered, ask questions if you’re not sure of something and double-check that the information you entered is accurate.

MORE TAX TIPS

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