Criminals are increasingly targeting residential mailboxes and U.S. Postal Service blue collection boxes looking for bank checks and valuables, according to officials.

At least four blue boxes were hit in York County this summer, with filled-out checks being a prime target, according to United States Postal Service Inspector Christiana Kasian. The thefts were reported in Shrewsbury, East York, Felton, and Windsor in July.

Such thefts are contributing to advice from officials to be careful about where you deposit any mail with cash, checks or valuables. Thieves have broken into stand-alone blue collection boxes or reached down through mail slots to fish out mail. They also target residential mailboxes with flags up, hoping to strike gold, especially if it appears items have been left in mailboxes for a while.

The U.S. Postal Service and the Postal Inspection Service are taking steps to reduce robberies of mail carriers and mail theft, both of which have contributed to a spike in check fraud.

Mail thefts from homes and blue collection boxes are on pace to increase 30 percent this year. The postal service logged 38,500 thefts in fiscal year 2022 and is on pace to record 50,000 thefts this fiscal year, the Postal Service said in May.

Robberies of letter carriers is on pace to nearly double this fiscal year as well. If the statistics hold, 610 carriers could be robbed by the end of the fiscal year, illustrating how popular mail is for thieves.

“We do know that people travel around the country to steal mail [from large mailboxes],” she said. ”We have a lot of bi-ways and highways through our area [central Pennsylvania], so it’s quick and easy for fraudsters or criminals to travel around the midstate.”

She said criminals are looking for anything of monetary value — from cash, checks, gift cards, money orders, and personal identifying information to access financial accounts.

The crime doesn’t end when fraudsters get a hold of mail, as criminals can use stolen information for identify theft or bank fraud, Kasian said.

Kasian said criminals also use “check-washing” schemes — using liquid chemicals to erase all payment information previously written on the check — to cash fraudulently obtained checks. Some scammers even go as far as using copiers or scanners to print fake copies to cash.

Postal inspectors recover more than $1 billion in counterfeit checks and money orders every year, according to the U.S. Postal Inspection Service.

Most banks recommend people use gel ink pens to prevent check washing because gel ink binds to the paper better, dries faster and does not smear, making it easier to read and more durable than ballpoints.

But lawbreakers can be relentless, according to Kasian.

“If a fraud still wants to remove information on a check, they will find a way to do that,” she said. “Whether that’s using a razor to scrape the writing off, or washing a check in acetone, they will find a way to remove the information and change it.”

“Sometimes they will deposit it as is without changing the check at all,” she continued. “Sometimes they’ll just write over it or use white out.”

To try to combat thefts, the postal service has added:

More secure collection boxes: The Postal Service plans to deploy 12,000 high-security collection boxes, which are more difficult for criminals to break into.

Electronic locks: The Postal Service is replacing 49,000 older key locks with electronic locks on blue collection boxes in several specific cities with plans to expand to other cities.

How to protect yourself

Promptly pick mail and packages up. Don’t let incoming or outgoing mail sit in your mailbox.

Inquire about overdue mail.

Send packages using the postal service’s “hold for pickup” if necessary, which will keep the item at the post office until the recipient can pick it up.

Do not send cash through the mail.

Follow tracking services for packages.

Deposit outgoing mail through boxes or slots inside your local Post Office or at your place of business or by handing it to a letter carrier.

Sign up for the Informed Delivery service on the USPS website and get daily digest emails that preview your mail and packages scheduled to arrive soon.

If you see someone actively tampering with a mailbox or you see someone following your mail carrier, report it immediately to the police.

Become involved and engaged in your neighborhood via neighborhood watches and local social media groups to spread awareness and share information.

If someone is a victim or witness to a mail-related crime, please report to Postal Inspectors at 877-876-2455 or online at USPIS.gov.