Originally Posted by
Swanhunter
Under a tenner, round up to the next pound
£10-20, add £1 and round up
£20+ add £2 and round up.
Thanks. This has always been roughly my system in London cabs -- casual, proportional, and you're not seen fussing over the odd 50p.
In New York, for contrast, you can swipe-and-pay in the backseat and the screen will suggest percentage tips to add. So you can make a $7.80 fare total $9.21 (adding a generous 18 percent). This will actually save you money by avoiding round-upping; the natural tendency on a $7.80 fare would be to toss the cabbie a tenner and be done with it.