Unlike the US or some countries in Europe, tipping culture is far less defined in Budapest. While in high-end restaurants you’ll find that a 10 – 15% service charge is automatically added – especially for groups – you’ll find that in smaller, more local places, wait staff leave it up to your generosity.
Generally speaking, if you liked your meal, feel free to leave about 10%. Most places won’t have the facility for you to leave a tip via card, even if you’re paying for your meal that way, so come with some small bills handy. Elsewhere, in bars, cafés and for taxis and salon visits, tipping isn’t expected, but rounding up your payment is certainly appreciated.