More people from New Zealand are moving back home, especially from Australia, as the country sees its first annual net gain in migrants from Australia in over 20 years.

New Zealand had a record annual net gain, more arrivals than departures, of migrants in the October 2015 year of 62,500. It resulted from a record 120,100 migrant arrivals and 57,600 migrant departures, according to the latest data from Statistics New Zealand.

The annual net gain in migrants has been setting new records for the last 15 months. In October, net migration passed another milestone with the first annual gain in migrants from Australia in over 20 years.

The change is due to fewer New Zealand citizens departing for Australia and increased arrivals of both New Zealand and non-New Zealand citizens. Of the migrant arrivals in the year to October 2015 some 25,000 were from Australia, with two thirds being New Zealand citizens.

The data also show there were 14,300 were from India, with three quarters having student visas, 13,400 were from the UK, with about 80% having work visas or New Zealand citizenship, and 10,800 were from China, with just under half having student visas.

Seasonally adjusted figures also showed a record net gain in October 2015 of 6,200. Net migration has been regularly breaking records since August 2014, when it surpassed the previous highest ever net gain of 4,700.

The change in migration patterns comes as the Australian economy cools, with an increase in those returning also coming as fewer people from New Zealand move to Australia seeking work.

New Zealand Prime Minister John Key said that the record migration figures are a "reason to celebrate" as it marked massive turnaround in the population New Zealand had been losing to Australia.

He pointed out that around half of the overall arrivals were either international students, who made money for New Zealand, or New Zealanders arriving from overseas. Beyond that many of the arrivals fell into either highly skilled or investor categories, who added to New Zealand's economy.

"All of those things are either things that we can't control, wouldn't want to control or things that we should celebrate. The alternative to this is net migration showing huge numbers of people leaving our country. Show me a country which is booming around the world, where more people leave it than come to it. The answer is, New Zealand is highly placed as a destination that people would want to come and live in," Key said.

The data also shows that visitor arrivals to New Zealand numbered 229,400 in October 2015, up 9% from October 2014. Much of the increase was holiday visitors from China, up 43% from October last year.

In the October 2015 year, visitor arrivals totalled 3.06 million, up 9% from the previous year. Australia contributed 1.31 million visitors, China 335,400, and the United States 237,700.

Chris Tennent-Brown, a senior economist at ASB, believes that people from New Zealand are relocating from Australia and not moving to because their prospects were not as strong as they once were.

Not everyone thinks the change is a good one. Some economists have warned that record immigration will increase unemployment as well as put pressure on an already strong Auckland housing market.