Hi @Simon2920 yes you have to increase rates, as the service fee will now be deducted from your side in full. The idea is that you and the guest can then carry on with little impact (although a host may now reach a threshold such as mandatory VAT registration, sooner).
You should be able to find a tool, either in your emails from Airbnb or on your host dashboard, that does the updating for you.
I can't post a link because I don't have it - hopefully a UK host can post it here if it's hard to find.