Commuters face changes to the collection of fees for using a bridge or ferry to cross the Tamar River.
The tag system for cars will replace vouchers completely from March
Vouchers for vehicles using the Tamar Bridge and Torpoint ferry will no longer be sold from 31 January.
The 15-year-old voucher scheme is being replaced by the £4m TamarTag system which has run for a year.
The tags are attached to vehicle windscreens and automatically register when a driver uses either crossing. A pre-paid account is then be debited.
Old vouchers will still be accepted until the end of March and can be swapped for tag credits or cashed in.
The tag system for cars will replace vouchers completely from March.
The decision has been taken because of a very high demand for a new electronic tag system.
Two thirds of discount crossings are now made using the new electronic tag system.