A number of customers with TomTom sat-navs have been told that their devices will no longer receive map updates.
“Your maps will become out-of-date and as such navigation will be less accurate,” the firm told customers.
“It has become clear that some of our older generation navigation devices do not have sufficient resources to run the newest maps and software.”
Some devices that were on sale in 2017 will stop being updated and the BBC has asked TomTom for comment.
The firm has published a list of affected models online.
In an email to customers, the firm added: “We will continue to provide quick GPS fix updates so your device will continue to function as it does now.”
The BBC has spoken to one user who was only given her sat-nav at Christmas, though the model was first released in 2011.
Paula Hatcher’s partner bought her the Start 20 device because her previous sat-nav – the same model – had not come with lifetime maps.
“I haven’t even had the opportunity to update it even once, since the email I received this morning [advised] the withdrawal of lifetime maps,” she said.
TomTom’s sales of devices direct to customers have recently been in “severe decline”, according to analyst Chris Jones at Canalys.
“Clearly they’ve identified a business market for future growth – that includes navigation and traffic services integrated into cars,” he explained.
He said the market for personal sat-navs had been eroded by the rise of smartphone apps that offer similar services and frequent updates.
“Within months the [sat-navs] will quickly become out-of-date when those updates stop appearing,” he added.
“It’s not just new roads, it’s [information about] features on roads – road signs, speed limits, rights of way and crossings.”