The owner of a South Auckland liquor shop is under fire for his decision to allow people to use Afterpay; allowing them to drink now, pay later.

Panmure Bottle O' recently began offering its customers the option to Afterpay their alcohol – paying off their debt in instalments.

Dr Nicki Jackson, the executive director of Alcohol Healthwatch, told the Herald there was "unanimous disbelief" that kind of service could be offered for what she says is New Zealand's "most harmful drug".

"Accessibility of alcohol in New Zealand is already high and I have concerns. During the pandemic a lot of people are drinking more and there is an exacerbation of mental health issues due to this pandemic, and high levels of alcohol harm. It's just not in the right direction."

Jackson told the Herald New Zealand must realise alcohol is "our most harmful drug".

"It shouldn't be classed alongside other retail."

She said last year it was only boutique alcohol retailers who were using Afterpay, but noted the pandemic could "absolutely change that".

"Now it's getting into the mainstream and that's really, really concerning."

It is also of concern to Maungakiekie-Tāmaki Local Board chairperson Maria Meredith.

"From a personal perspective we have major issues in our community around alcohol harm," she told the Herald.

"By providing it as Afterpay you're just opening up a can of worms and making people who are already vulnerable more vulnerable."

Meredith added the store might face personal repercussions for the decision too.

"Like anyone else, they may come under public opinion and public pressure to change their practices. If there's enough people objecting to it, it could force that business to not offer that service."

The owner of the liquor store says the decision has already begun to draw negative attention.

"If you check on Facebook you'll see I've gotten so many bad comments, I'm a bit worried I've spoilt my name."

He told the Herald he began to offer the service to try and boost his business, which he said had been struggling.

"We're not doing so good in the business; everything is going up [in price] and so many shops are doing it."

However, he says there has been little uptake.

"I'm not getting any customers on the Afterpay at the moment."

Despite the negative attention, he has not decided to remove the service yet.