Can you stop scam calls before they start?

She had read plenty about the phone scams from imposters posing as Internal Revenue Service employees, but Sharon Gustin had never heard one herself.

The former tax preparer finally got one over the weekend. The automated message told her that she would face legal action if she didn’t call the number provided and pay the IRS immediately.

The IRS doesn’t call to demand immediate payment or threaten legal action. Any call suggesting otherwise is bogus.

“I just hung up as soon as I knew what it was,” Gustin said.

She got another chance to hang up that same day. Another call came Monday. Gustin called Argus Leader Media to remind people that the calls are still happening.

Gustin had another question, though, and it’s a pretty good one: Is there anything you can do to stop these IRS calls before they start?

There’s no perfect answer yet. Tax scammers can mask numbers to conceal their location, and the numbers themselves change regularly.

Even so, there are places to look. Entering the number Gustin jotted down into whitepages.com's reverse phone lookup feature showed that the number was tagged as "Scam or Fraud” and “Flagged as Extortion.” More than a dozen commenters noted that the number was attached to a tax scam.

If you use a smartphone, there’s an app from whitepages called Hiya that will block calls associated with scam numbers. The app stops calls from suspected scammers and informs you that one of them tried to reach you.

The app launched this spring. Its website says it analyzes 400 million calls a month to determine which numbers are connected to spammers, and that Hiya can take reports of potential scams from users.

Hiya isn’t the only app offering such services. Apps like PrivacyStar, Truecaller and Mr. Number can let you block calls from scammers and unknown numbers. Search your app store for “phone blocker” to see the options.

MORE:Reader's Watchdog stories from John Hult

For landlines, the technology isn’t quite so advanced. The Federal Communications Commission has pushed for a solution, but companies like Midcontinent Communications aren't able to block suspected scam calls before they come in. 

Midco offers landline tools to block anonymous callers and private numbers in a blanket fashion and to block specific numbers, but the numbers need to be known by the customer first. 

“It’s not based on any sort of algorithm,” said Erin Johanning of Midcontinent Communications.

CenturyLink, which has 83,000 landlines in South Dakota, offers similar tools, outlined in this link.

"We understand consumers' concern about the problem of unlawful, automated calls and share their frustration with mass telephone solicitations," said spokeswoman Rachel Woodman. "CenturyLink currently provides several tools that can help reduce the recurrence of unwanted calls, which include our no solicitation and security screening products or privacy ID, where available."

Scammers will surely continue to evolve, so there's no guarantee of blocking the disreputable from your phone lines entirely. If you get a scam IRS call, you can report it to the Treasury Inspector General for Tax Administration at 1-800-366-4484.

For Gustin, unfortunately, her calls were coming in on a landline. Her children keep telling her to get a smartphone, she said, but she's not sold just yet. As for the IRS calls:

"It's an annoyance, but I know I'm not going to fall for it," Gustin said. 

John Hult is the Reader's Watchdog reporter for Argus Leader Media. Contact him with questions and concerns at 605-331-2301, 605-370-8617, twitter.com/ArgusJHult   or  Facebook.com/ArgusReadersWatchdog.