The biggest note in the UK is the £50 note. In my entire life I have handled one three times. Each time not a single business would accept them and I had to go to a bank to deposit it instead. Looks like it's a voluntary ban to me.
I agree, that may be a bit extreme.
In the Netherlands it is quite the same actually. 100 euro notes and up are mostly not accepted by shops, just because of the risk of running into counterfeit notes.