I'm off to Luxembourg with some mates tonight. We are travelling out early tomorrow morning with P&O and back on Monday with SeaFrance.

There were originally going to be four of us but one lad has been told he has to work (which he is extremely cheesed off about, but that's another story), leaving three. Unfortunately, the one who can't come is the one who was providing the transport, so we have had to go in a different car.

The question is whether we will run into problems because the car registration I gave on both bookings will differ from the actual car we turn up at the port in.

I have had this situation before with Norfolkline, where they didn't bother at all. However, Sea France are trying to charge me £10 to change the registration - I haven't been able to get through to P&O to find out.

It strikes me as a bit cheeky to charge just to change the registration - I could understand if we were now going in a minibus rather than a car or something like that, but it'll be the same size of car and is purely a reg change.

The ferry companies' web sites tell you that if you are travelling in a rental car for example, to put TBA in the car reg field when booking and they will just update it when you arrive. Presumably they wouldn't charge for that, but because we put a different reg in rather than TBA they want to charge?

Does anyone have any experience of a similar situation and what happened?