Auckland ratepayers are about to be hit with their first bill under the new single rating system since the super city was formed - and some can expect a hike.

Auckland City Council announced on Sunday that those in northern and western regions can expect their bill to arrive by Thursday, while the rest of the city will have theirs the following Tuesday.

Each of the eight councils which previously made up Auckland had its own ratings system.

The new system is based on the capital value of a property.

Mayor Len Brown says some ratepayers can expect to pay more and others less.

But, he says, since the councils were combined rates have gone up by an average of 3.6 per cent each year compared to 5.7 per cent under the former councils.

Mr Brown will be visiting areas of Auckland over the coming weeks to explain the new system.

Ratepayers can be assured that the council has not been recklessly spending, he said.

The city's wastewater bill, which was previously paid through rates, is now the responsibility of Watercare or Veolia Water and now appears on the bill from them.