Identity thieves go to great lengths to steal your identity. But all too often, scammers latch onto a relatively easy way to do it, using a loophole in the post office’s change-of-address system.

Change-of-address forms are readily available at any post office. All you have to do is fill out the card and drop it in the nearest mailbox. Scammers can then collect your mail at a vacant home or fake address.

Police say the crooks are usually long gone by the time victims complain.

A 2008 Inspector General report warned that the “postal service should improve controls to ensure proper authorization and validation of COA request.”

Postal officials say letters are sent to both the original and new addresses once a request has been submitted, so you will get some warning if someone else has forwarded your mail and you can take steps to cancel it at your post office.

The post office also says that change-of-address requests made online have one protection — you have to use a credit card to pay a fee. And, in effect, that can be a check on whether the actual homeowner is ordering the change.

The postal service also says complaints like these are rare, but it continues to implement security enhancements.