PLUNKET'S car seat service in Masterton is to close at the end of June in response to falling customer numbers.
Masterton's car seat rental stock had halved since 2008, said Plunket car seats exit manager Catherine McLaren.
The scheme is 30 years old but people's habits had changed, said Ms McLaren.
"Instead of hiring car seats from Plunket they're more likely to buy a seat, or hire one online."
The number of Plunket car seat sites has declined from 283 at its peak in the 1980s, to about 60 today.
The charity would honour all existing bookings, she said.
"Our priority is our current customers and those who have bookings, making sure they're looked after.
"We have several options available, and we're committed to working with families to ensure their needs are met. We will have ex-rental seats available for sale at a reasonable price to our current clients and those with bookings in the first instance."
She said that Plunket had started contacting customers as their invoices become due.
"We'll be in touch with all of our customers in due course, but if you have questions please get in touch."
Families without a booking could still hire car seats from Plunket in Wairarapa at 24 Worksop Rd on a short-term basis and buy a car seat from Plunket up to the end of June, or get advice about car seat installation and fitting.
Families with a community services card could also buy a booster seat from Plunket for the reduced price of $50 thanks to a partnership with ACC. The service is open Tuesday 10am to 1pm, Thursday 1pm to 4pm, and Saturday 9.30am to 11.30am.
She said the decision did not affect other Plunket services which continued to operate as usual.
Plunket aims to continue supporting families nationally and in the Wairarapa through car seat safety education and advocacy. In the coming months, Plunket will develop a new national injury prevention strategy and work across each region to devise car seat safety programmes in response to the needs of each local community. Plunket is a charity and all of its programmes are dependent on funding.
"We'd like to thank our customers in the Wairarapa area for their support," said Ms McLaren.
"We're proud to be part of the community and of the work we've done over the years to help families keep their children safe on the roads. We're looking forward to building on this success."
If you are a Plunket customer and you have questions about the changes to Plunket's car seat service contact the car seats team on 06 378 6101