According to a document leaked to the Web site Boy Genius Report, Verizon Wireless has plans to double its early termination fee on “advanced devices.”

Verizon did not reply to requests for comment by press time, but if the documents are accurate, subscribers will be charged $350 to cancel service before the terms of their contract are up beginning on Nov. 15.  Verizon currently charges a $175 cancellation fee.

According to the documents, the new cancellation fee will decrease by $10 for every month of completed service. The documents did not specify what constituted an “advanced device,” but it is speculated that Verizon is referring to smartphones.

Verizon is currently offering a buy-one, get-one-free sale on its BlackBerrys. That has sparked a grey market trade in the devices, where subscribers purchase the handsets from Verizon, pay the $175 cancellation fee, and then resell the device on sites like eBay for well over what they paid for the device.