The FCC has approved new rules expressly banning unauthorized charges on phone bills, a practice that was already illegal under federal law but never formally codified within the agency. It’s the first time the commission is adopting an explicit rule.

The new rules ban unexpected phone bill charges, also known as “cramming” many services that a customer didn’t ask for onto a bill. The rules also ban the practice of tricking a customer into switching phone carriers. From now on, if a company is found to have used deception to obtain your consent to switch carriers, your consent will be deemed invalid.

Changes are also being made to how third-party verification services, which are supposed to validate a sale or carrier switch, confirm that a customer really intended to take action. The third-party verification process will no longer need user approval for every service purchased, in order to save customers time and streamline the process. It’s a change that’s supposed to be helpful, but it sounds like it could lead to unexpected charges when you aren’t paying attention. Finally, carriers that abuse third-party verification, such as by editing out parts of a customer’s phone call with a third party to make it sound like an approval to switch carriers, will be suspended from using them for several years.

In the past, the FCC fined violators and worked to eliminate practices like unauthorized phone bill charges and misleading customers during sales calls, but it was working off of broader protections in the Telecommunications Act of 1996 and the “truth-in-billing” rules the commission adopted in 1999. By codifying its prohibitions into formal rules, the commission is hoping it will have firmer ground to tackle these issues.