PHILADELPHIA — Although it pales beside the loss of a loved one, today’s complex financial system has created a new headache for grieving relatives to cope with: identity theft.

Risk of this disturbing crime, in which a thief poses as someone else to obtain credit or commit some other fraud, doesn’t necessarily end when a person dies, as the family of Zal Chapgar discovered recently. Chapgar’s death at age 23 devastated his close-knit Blue Bell, Pa., family. Then, amid their grief, they suddenly faced a rash of phone calls from creditors seeking to verify that their son had applied for new credit cards.

American Express. Citibank. Best Buy. At least four calls, each bringing an extra measure of heartache.

“We thought it was a freak thing,” said his mother, Kerban Chapgar. “It was only after the second call that we started to pay attention.”

The calls to the Chapgars illustrate the risks faced by any potential victim of identity theft — which is everyone. The steps they took to stop them illustrate the methods people can use to avoid falling prey and spending money needlessly on identity-theft protections.

First, a few basics:

Last year, identity theft drew more than 258,000 complaints to the Federal Trade Commission, a third of all complaints. It eclipsed complaints about catalogue sales, Internet auctions and sweepstakes.

Formal complaints are the tip of an iceberg. In 2005, an FTC survey estimated that 8.3 million Americans fell victim to some form of identity theft. The most common involved misuse of a victim’s existing accounts. The most serious frauds, including the opening of new accounts in a victim’s name, affected an estimated 1.8 million people.

Identity theft can be a big hassle to any victim, and is quite costly to some. One in 10 victims put the cost of the crime at $1,200 or more. On the other hand, more than half reported no out-of-pocket costs, and among victims of new-account fraud, the median loss was $40, the FTC found.

The government is slowly pushing the credit industry to address what consumer advocates have long argued is a key cause of identity theft: the overly easy granting of “instant credit” both to consumers themselves and to thieves armed with their victims’ personal data. In fact, the Chapgars were apparently spared additional hassle because of a new FTC rule designed to highlight “red flags” that may signal identity theft.

One of the new requirements, in effect since Nov. 1, requires creditors to take extra steps to verify applications when an address differs from the one in the applicant’s main credit file.

But most of the changes, such as watching for activity on long-dormant accounts, were delayed until May, thanks to pressure from the business community.

Representatives of the credit-reporting agencies say what happened to the Chapgars is relatively rare. It was likely the work of an opportunistic thief who saw their son’s name in the news and matched it with identifying information, such as his Social Security number, that thieves can often obtain.

“It’s probably one of the last things you want to think about in a situation like that,” said Tim Klein, a spokesman for the credit-reporting agency Equifax.