An analysis of more than 1 billion phone calls placed during 2018 suggests there's a very good reason not to answer the phone tomorrow.

Yes, tomorrow specifically.

At least, don't answer any calls coming in from numbers that you don't recognize. The reason is that during 2018, the number-1 day by far for what the researchers call "negative robocalls," meaning scam, fraudulent or nuisance robocalls, was April 17.

What was so special about April 17? Last year, it was Tax Day--which is normally on April 15 but sometimes gets push a day or two back if the 15th happens to fall on a weekend or a holiday.

This year, no such luck. Tax Day is tomorrow: April 15.

143 million nusiance and high-risk calls

The data analysis was released earlier this year by Transaction Network Services, Inc. (TNS), which describes itself as a supplier of networking and integrated data services.

"Nearly 143 million nuisance and high-risk calls were placed on Tax Day 2018, as scammers often pose as the IRS in an attempt to trick taxpayers into providing money or personal information," the firm said in a press release.  

Given that the population of the U.S. is about 329 million, this means about 43 percent of Americans were targeted with at least one "negative robocall" on Tax Day last year.

Unfortunately, TNS predicts that the problem will be even more acute this year.

"Scammers are seizing on residual taxpayer confusion from the government shutdown," a company spokesperson said, "and TNS has already tracked multiple tax filing and IRS related robocall scams in the initial weeks of this year."

Add to that simply the fact that as many as 45 percent of all incoming calls to mobile phones are now expected to be coming from spam or other negative dialers and robocalls, and it paints an ugly if unsurprising picture.

Also: Tuesdays

I'm going to assume that most of the people reading this article are unlikely to fall for the types of tax-related scams and tricks involved in these calls. But calls targeting immigrant communities, the elderly, and other less sophisticated targets abound.

Among the other takeaways from the TNS study:

  • Notwithstanding the fact that Tax Day is on a Monday this year, in general Tuesdays are the worst for negative robocalls. Sunday had the fewest.
  • April is the worst month for robocalls in general, constituting 10 percent of the traffic. December is better: only 6 percent.
  • The worst place to live if you want to avoid negative robocalls: South Carolina, which gets the most of them. Its neighbors North Carolina and Georgia were #2 and #3 on that list.
  • Finally, the city with the most incoming negative robocalls during 2018 was San Diego, while Kansas City was on the other side of the list: the city from which the most negative robocalls were made in in 2018.

So, I guess the answer is: don't answer the phone. Or if you insist on doing so, make sure you use somebody like Lenny.