Rental Cars London

You can check here:-

To view the CROSS BORDER or FERRY terms and conditions. At STEP2 of our 3 step online booking process, alongside the car photo of your choice, there is a link entitled “IMPORTANT INFORMATION”. Clicking on this link will open an additional smaller window, with the terms and conditions appertaining to that particular car/supplier. Choose then the CAR tab and look under TRAVEL RESTRICTIONS Try a few different suppliers as each supplier/vehicle type may have a different cross border rule.

I had a look as well and see that Alamo allows it and their rate includes unlimited mileage. For Sixt counts the same, but they divide the permitted countries in 2 zones. Germany is in zone 1 and Poland in zone 2. Certain types of cars can enter zone 1 countries, other types can entry zone 2 countries.