There's definitely cases where UK English has adopted a new word but American English hasn't. I was surprised to see the word "coupon" used in old UK literature. "Voucher" is the more common word nowadays. People would accuse you of being Americanised if you said coupon.
Stig of the Dump is set in an informal place people dump rubbish, if I remember correctly, which is where people are more likely to use the term (e.g: "what a dump"), but if you are talking about a managed place it is taken to be disposed of properly, tip is by far the more common term I hear used.
I also call my discount-loving fellow Brit friend ‘coupon boy’ rather than ‘voucher boy’!
It was always the dump when I was growing up (mid 70s, northwest.)
I suspect might be one of those regional things like scone/scone[1].
1. It’s pronounced “scone” and I will fight anyone that says otherwise!
I'm not sure if this is actually correct usage in those countries, or slang, but it certainly feels much more like slang, and felt virtually impenetrable, even to someone who's been exposed to a fair but of UK-isms in his life.