NEW YORK — Months after business owners and other taxpayers have filed their returns with the IRS, thieves try to scam people out of money or personal information.

Although scammers operate year-round, the IRS says they step up their activities in the summer, when taxpayers can expect to hear from the agency with questions about returns filed during March and April.

Thieves typically use phone calls or emails that sound or look official, and that can sound threatening. The scammers’ hope is that people will believe it’s really a call from the IRS or that they’ll click on a link in the email, allowing cyberthieves to invade their devices and steal personal information.

One important fact can help protect against scams: The IRS does not initiate contact with business owners or other taxpayers by phone or email seeking personal information like Social Security numbers or financial information like credit card numbers.

If the agency has questions or needs to inform a taxpayer about a problem, it usually will do so via U.S. mail. It does not leave prerecorded messages or make threats — some scammers have warned that their targets will be arrested if they don’t return calls.

Another important fact: The IRS must give taxpayers a chance to appeal a tax bill before it takes any action against them.

Email scams are common and the IRS says they do target small businesses. They include phishing scams that encourage or demand that an email recipient click on a link or attachment. That click gives cyberthieves access to information like passwords and in turn, money in bank or credit card accounts.

Owners and their employees should never click on anything in an email unless they are certain it’s legitimate. Thieves are becoming more sophisticated about making emails look authentic.

Dealing with phone calls or voicemails is easier: Hang up on the caller, or delete the voicemail.

Sometimes the scams do arrive by mail. The IRS recently warned about a new scam that claims a recipient owes taxes to a bogus agency, the Bureau of Tax Enforcement, and directs how and where to pay the bill. There is no such bureau in the government.

Many scams about taxes purportedly owed demand payment using a specific method like a prepaid debit card or wire transfer. However, the IRS does not use those methods. Scammers may also specify who a check should be made out to, and it’s likely to be a fake name. All legitimate tax payments by check must be made out to “U.S. Treasury.”

Some scammers will show up at a home or office claiming to be an IRS employee. The government generally does not show up in person unless there are special circumstances, usually tax bills that are overdue and that have been sent to a collection process.

But by the time that happens, the taxpayer has already gotten several bills from the government.