If you plan on unlearning some bad habits this year, add this one to your list: Abbreviating the year on your checks and legal documents. As USA Today reports, the practice that was harmless in 2019 could make you vulnerable to fraud in 2020.

Because this year starts and ends with the same two digits, documents dated with the abbreviation 20 are easier to forge. If a scammer wants to make it look like a contract you signed this year was actually filled out last year, all they'd have to do is add 19 at the end of the shortened date. This tactic could be used to trick you (or the authorities) into thinking you owe a debt on payments you haven't agreed to start sending yet.

Abbreviating the year also makes it possible to forge dates in the future. If a check signed this year becomes inactive before it's cashed, someone could possibly change the date to 2021 in an attempt to cash it late.

Fortunately, this is one potential scam that's easy to combat. When signing important documents this year, always take the extra second to write the full date. This makes the date much harder to tamper with. It's the same reason you should always fill the entire line of the check when writing the payment amount.

Looking for more ways to protect yourself from scams? Here are some habits that could leave you vulnerable online.

[h/t USA Today]