Our changing modern society is behind the dramatic drop in the number of New Zealanders tying the knot, and getting divorced, relationship experts say.

Statistics NZ figures released today showed 19,237 marriages were registered to resident New Zealanders last year - a figure fewer than 20,000 for the first time in more than 12 years.

Jill Goldson, director of the Family Matters Centre in Auckland, said New Zealand is following similar social trends shown in the UK and US.

Young people are under less pressure to get married in an increasingly secular society where de facto relationships now have the same legal status as marriage when it comes to children and property, she said.


"Social change has changed the meaning of marriage for the current generation," said Ms Goldson.

"Gone are the days of contested divorce and assumptions about custody.

"Being born 'out of wedlock' no longer frames children's lives in the way that it did."

Ms Goldson said her practice saw "a lot of people dealing with the reality of the rearranged family system".

"The main focus of my research and work is how to help people navigate the new social structures that statistics such as those released today have demonstrated," she said.

But Family First NZ said the drop in weddings should act as a "warning bell to society" over the benefits of marriage.

"The question we must ask is whether the decreasing rate of marriage has been good for society. The evidence suggests that it has caused untold harm and cost," said national director Bob McCoskrie.

The annual figures also reveal people getting married later in life.

Pablo Godoy of Relationships Aotearoa, a not-for-profit professional counselling and family therapy provider, believes the trend for more mature brides and grooms could be behind a continuing drop in divorce rates.

Last year, 8279 married couples divorced, compared to 10,491 in 2003.

"In the past 10 years there has been a pretty consistent trend of reducing divorce numbers overall. We're not looking at an anomaly," Mr Godoy said.

Older couples are more likely to engage in "courageous conversations" around finances and life goals, he said, which tends to bode better for successful long-term relationships.

"I'm betting that [maturity] is one of the main contributing factors to the dropping divorce rate."

New Zealanders are also getting better at talking through relationship issues, and in seeking professional help before the divide gets too wide, Mr Godoy said.

In 2013 there were 209 same-sex marriages and 187 civil unions registered to New Zealand residents, with an additional 46 to overseas residents.

Since same-sex marriage became legal in New Zealand last August, the number of same-sex civil unions was almost halved compared with 2012.

One Auckland gay celebrant Barry Davis said 2013 was a quiet year.

"I didn't have many same-sex marriages last year, and no civil unions."