Thousands of Kiwis have received a scam text message about an unpaid customs charge for a package delivery.

The text, sent from an Australian mobile number, says: "We have attempted to deliver your package UPS016448296GB, but there is an unpaid customs charge. Follow the instructions here: "

Scam alert: anyone else receive one of these recently?

— Seán Gillespie (@SeanDG) November 17, 2020

Netsafe chief executive Martin Cocker said the agency has received thousands of reports about the scam.

"It is particularly prevalent at this time of year as more people are shopping online and expecting a package so potentially more likely to fall for it," he said.

"So far this quarter, Netsafe has seen a 65 per cent increase in reports related to the latest iteration of this scam compared to the last financial year."

He said scammers obtained lists of people's mobile numbers from social media and from databases stolen from legitimate companies and sold on the "dark web".

"The reality is that plenty of big sites that New Zealanders use have been breached," he said.

"Most of us use the same email addresses and phone numbers and even passwords for a long time, and we can be targeted."

He said people should not click on any links in messages asking for money or personal details.

"You go to the agency that you know is the right place. Don't click links," he said.

The Customs Service said it has received 60 calls and a handful of emails about the scam over the past two days.

"Customs never contacts individuals or businesses about the arrival of goods in New Zealand because goods are not physically received by Customs," it said.

"All imported goods are delivered to warehouses run by licensed freight forwarders which are known as Customs' Controlled Areas. Freight companies contact their client/s when import tax is to be paid."

The Ministry of Business, Innovation and Employment's national manager of consumer protection, Mark Hollingsworth, said the ministry was also aware of the package delivery scam, which appeared to be taking advantage of people buying more online since the coronavirus pandemic started.

"Due to Covid-19, scammers assumed people had deliveries on the way and therefore targeting a wide audience," he said.

Netsafe said this week that New Zealanders told the agency about losses of nearly $19 million from online scams and fraud in the year to June, down from $23m last year and a peak of $33m in 2018.

Cocker said the reported numbers were likely only a small percentage of actual losses because many people were too embarrassed to report what they had lost or did not know who could help.

He encouraged people to report scams so that phone companies can block phone numbers and email addresses being used by scammers, and so that details can be passed to police.

Scams can be reported online to Netsafe or by free text 7726 to the Internal Affairs Department.

The biggest reported losses in the past year were investment frauds, up from $4.7m last year to $7.1m.

Kiwis also reported losing $4.7m on romance scams, $3.3m on frauds involving products and services, $1.1m on false prizes and grants and $700,000 on phantom debt collectors.