Hi, I recently accumulated numerous parking tickets for

Your friend is partially right.
They do not generally bother to sue. The reason for that though is that most people only accrue one fine. For one fine its not worth the manpower. For nine it might be. Therefore there is a risk of being sued.
In terms of the amount of the claim, your friend is wrong. To claim in breach of contract you have to show one of two things. The first is that you have suffered loss. That is what your friend is thinking. He is trying to suggest that you put the company to proof over the sum of their loss. I have to say that Im afraid I think they have a claim for more than the sum of the parking. They are entitled to admin costs apart from anything else. However, they can also try to argue that the sum of the fine was agreed under the contract. It depends what the signs at the location say. If they say that parking at X location will incur a fine of Y amount then that would apply. You could still argue its void under UCTA but nobody has succeeded on that point yet although, of course, not many of these go to court.
Can I clarify anything for you?
Jo