Which of the following is a scam?

— You get a phone call saying you owe money to the Internal Revenue Service and should pay by way of an iTunes card.

— A caller says she is an IRS official demanding immediate payment of overdue taxes, and the number on your caller ID appears to be from the local IRS office.

— A caller identifies himself as a law enforcement officer and says you face immediate arrest if you don’t wire money for overdue taxes.

— An email bearing an official-looking IRS logo asks you to “update your IRS e-file immediately.” The email mentions IRSgov — without a dot separating “IRS” and “gov.”

If you answered that all of the above are scams, you are correct.

The investigative arm of the IRS says that 1.8 million people have reported receiving impostor calls. More than 9,600 victims have been scammed out of more than $50 million.

Phishing and malware incidents rose roughly 400 percent during the 2016 tax filing season. Despite officials’ best efforts to curb the increase, it’s expected that the numbers of tax-related scam attempts will continue to grow.

Increasingly popular with scammers is the robo-call. The crooks leave urgent call-back requests, demanding payment of “back taxes” with gift cards. IRS officials say such demands are clear signs of a scam.

Other callers may ask for payment of a nonexistent “federal student tax.” People they call are told to wire money — another sure sign of a scam — with threats of legal action unless payment comes at once.

Another scheme involves a call saying the IRS “just needs a few details” to speed up the processing of your refund. The scammer tries to get personal information such as Social Security numbers, bank routing numbers or other sensitive data such as credit card numbers.

Human resources and payroll professionals have been targeted as well, through requests for information about employees. A scammer posing as the company’s CEO requests personal and financial information, including Social Security numbers.

In an effort to catch scammers and identity thieves, the IRS is delaying refunds this year for anyone claiming the earned income tax credit (EITC) or the additional child tax credit (ACTC). That move is expected to give the IRS added time to weed out more sophisticated fraudulent returns. It may also hurt lower income taxpayers who file early and likely will be waiting at least until late February for refunds. Offers to “help speed up your refund” may be more scams.

Sen. Susan Collins, R-Maine, chairs the Senate’s Special Committee on Aging, which has published a guidebook on avoiding scams. Read it online at aging.senate.gov/imo/media/doc/217925%20Fraud%20Book%20Final.pdf. You also can call the committee’s fraud hotline (1-855-303-9470) for information or to report fraud attempts.

The IRS offers a summary of our legal protections in the Taxpayer Bill of Rights at irs.gov/taxpayer-bill-of-rights.

Consumer Forum is a collaboration of the Bangor Daily News and Northeast CONTACT, Maine’s all-volunteer, nonprofit consumer organization. For assistance with consumer-related issues, including consumer fraud and identity theft, or for information, write Consumer Forum, P.O. Box 486, Brewer, ME 04412, visit http://necontact.wordpress.com or email contacexdir@live.com.