You can remind them that the pint is the liquid and not the head. I am sure they will respect that.
sadly not totally true... that insistence was in effect repealed in 1994.
https://www.ladbible.com/news/uk-law-sending-pint-back-to-bar-20221108"... British Beer & Pub Association (BBPA) ...
1993, the BBPA teamed up with the Department of Trade and Industry to create its own guidelines.
The Guidance Notes on the Dispense of Draught Beer by Free Flow and Hand Pull read: "A measure of a beer served with a head must include a minimum of 95 percent liquid."
While 95 percent is pretty good going, if you're not a fan of a mouthful of foam, you technically lose out on 19p's worth of beer for every £3.79 pint 92022 article - so more likely 25p on a £5 pint ], Kelvin Goodson explains.
Thankfully, the 'guidance notes' encourage pint drinkers to go up to the bar and ask for a top-up if they're not fully satisfied - a request which it says 'should be received with good grace and never refused, subject to avoiding spillage of liquid'. "
oen of my locals has oversized glasses so they can serve a pint to the line PLUS watever head naturally forms
didds
Just before I retired I took on an almost lost tax case with the Revenue which involved takings being accusedly underdeclared . We argued that this was due to very generous topping up of pints. I won at approximately 4.30 pm on my last day at work . The tax saving was several hundred thousand but could have nearly tripled with add ons for working back, VAT, benefits in Kind , Interest, Penalties etc!