Portugal has a complex system of tolls, people who come from outside that have rented a car have to be aware of it because they can run into serious headaches after a trip with unpaid fines. Until recently there were just a few main toll highways in Portugal and they used to work like any other system in the world, where you get a ticket and at the end of your journey on that road you pay. The bad news is that all this has changed with a new toll system that overlaps sometimes the very same road off and on.
Nowadays almost every main road in Portugal is a toll road and there is no way around taking them without going hours out of your way.
Regular toll Roads:
Here is how it works in a nutshell there are the main toll highways that work like any other highway at the beginning you get a ticket and when you go out you pay. You would best be served carrying cash because the tolls accept some credit cards and not others some debit cards and not others. Normally you are charged by distance.
The difficulty is with the Easy toll which is everything but what its name says it is. If you are local there is no problem because you can purchase a transponder. But the camera system will charge the plates of any car, including a tourist rental no matter what because you’ve crossed without a transponder. There are several ways to handle these tolls.
One option to handle this is to go to the website of EasyToll and prepay the Portugese Post Office a tag that they will send ahead of time to any address. This is largely unhelpful because how do you know what amount to prepay to the card?
The easiest way to navigate these toll roads successfully is to attach a credit card to your rental car license plate. On some of the major highways coming in from Spain near the border there is an ATM style system (there are only 5 or 6 in the main borders) where you can stop, insert your credit card to be charged and it will bill any toll expenses as you make them for the duration of your trip. Our personal experience we describe what we did because this is the route we took from Madrid, through Salamanca into Portugal.
If you are coming from the Salamanca route put into your GPS “Area de Servicio Alto de Leomil” This is known as the Aveiro –Vilar Formoso pay station and There is a BP gas station next to it as well.
Once you come to the Service Area Alto de Leomil be sure to pull off to the gas station on the right hand side, Do not proceed along the road to the toll booth. On the right hand side you will see this covered ATM style drive thru where you will register your car plate and attach your credit card for all the EasyToll incurrences you will have for the rest of your trip. The instructions at the booth are easy to follow. Be sure and note this covers you for the EasyTolls only, the regular ones you will still have to pay as you use them with cash or cards.
This is our experience for the route we took, but if you are coming from a different part of Spain we suggest you go here for descriptions of the other 5 toll entrances.