New Zealand has been described as having a "true" merit-based tipping culture. 

It is not customary and not required, however, for exceptional service (particularly with Concierges or in restaurants and cafes) a tip is always appreciated. The amount is at the discretion of the tipper and would generally be in the range of 10% according to the value of the meal/services. Hospitality and service staff in New Zealand are often students or part-time workers and even professionals are not paid well comparative to other countries. Wait staff in cafes/restaurants etc do get paid a higher hourly rate than their North American counterparts.

It may be appropriate to leave an envelope with the manager to be shared amongst the staff if it is too difficult to pick one individual!

On statutory holidays it is becoming common for restaurants, cafes etc to charge an additional service fee of normally around 10-15%. This is to cover the additional cost of employing staff on these days. This is in addition to the prices on the menu and signs will normally be posted stating that they will be charging this additional fee. However, this is NOT a tip/service charge that gets passed on to staff. It is an additional charge imposed by the owners to cover the increased wage rates they have to pay to staff on public holidays by law.

Hairdressers and food-delivery staff are not customarily tipped. Taxi drivers aren't generally tipped but they do appreciate it if you round the fare up to the nearest dollar so they don't have to look for change.