Fun "tip" (and I know this doesn't apply in the UK):

"Mandatory" or "Automatic" gratuities like this in the US are *not* legally considered tips, but are classed as "service fees". - https://shavitzlaw.com/mandatory-gratuities-are-not-tips-but-may-be-considered-commissions/

Historically (since 2012 or so), this has meant that a restaurant cannot count it towards the service workers wage.

But, recently, a federal district court (the 5th, in Florida) decided that since they are fees, not tips, the restaurant may, at their own discretion, keep those "gratuities" for themselves and have no obligation to distribute them to staff.

So, at least in the US, if you see a gratuity listed on a bill, don't assume that your server will see *any* of that money. If you care about that, ask if you can pay the non-gratuity portion normally, and give the "gratuity" portion to your server in cash. (I'm not saying they are required to allow you to do that).