When a group of people (friends/family colleagues) are dining at a restaurant, the bill will be shared equally regardless of who orders what in terms food and drink.
In this situation, those who order recklessly are in a much better position at the end of the meal than those who do so frugally. Diners who argue that they ate/drank less therefore should pay less are often ridiculed as spendthrifts and must accept their fate as victims of Geordie billing.
This term stems from Newcastle and Tyneside area, whose residents are notorious for their reckless abandon when it comes to eating and drinking.
Having anticipated that Geordie billing would ensue, John ordered the most expensive steak and elaborate cocktails during his work Christmas dinner.