Gizmodo is warning of a new scam involving text messages posing as FedEx tracking notifications.

Android and iOS users (including this writer) have received text messages including what purports to be a FedEx tracking number and a link to set delivery preferences. Clicking on the link, however, goes to a fake Amazon listing and survey.

As Gizmodo highlights, this is where the scam takes a turn. “If you proceed any further, the survey will then ask users for a range of personal information including their credit card information, which for anyone who hadn’t already started feeling suspicious, should set off serious alarms.

“Apparently, by entering in your address and credit card number and agreeing to pay a shipping fee for your “prize,” you are also signing up for 14-day trial that turns into a $100 recurring subscription for a range of products, which you will continue to get billed for every month until you figure out how to cancel the payment.”

One way to spot the scam is the alphanumeric nature of the supposed tracking numbers. FedEx tracking numbers are almost always exclusively numbers, whereas the fake ones include letters as well. Similarly, FedEx tracking numbers are 12 or 15 digits long, as opposed to the 10-digit fake ones.

Police departments are warning citizens of the scam and encouraging individuals to check any tracking numbers they receive directly on FedEx’s website, rather than following a link in a text message.