EE's roaming services have gone offline, leaving customers abroad unable to make calls, send texts and access data services.
Down Detector has confirmed the downtime, having received dozens of complaints an hour over the past few days.
Customers said that the apparent network-wide problem has left them unable to contact friends and family while out of the country for the past three days.
@EE can u give any idea how long until roaming problem fixed.In Corfu and need to be in contact with elderly mum in uk.? Buy Vodafone sim.— Jackie Hirst (@lucifair) August 1, 2016
I'm not impressed with @EE. There seams to be a network-wide issue with roaming but for some reason they're staying very quiet about it.— Rhammel Afflick (@Rhammified) July 31, 2016
EE has advised customers that it's aware of the fault and is working with the firm's roaming partners to get things back up and running.
An EE spokesperson confirmed the problem to V3 in a statement: "We're aware that some EE customers travelling abroad in certain countries are experiencing issues affecting their voice and data roaming services.
"We apologise to any customers affected, and we are continuing to urgently work with a number of our roaming network partners to resolve the problem as soon as possible.
"We recommend that customers try restarting their device or turning flight mode on and off, as that has restored service for a number of customers."
EE has yet to say when the problems will be resolved. We'll update this article when we hear more.
AlphaBay users had flocked to Hansa after it was closed down - not realising it had already been taken over by Dutch police
Microsoft closes in on $100bn annual revenues with sales weighing-in at $23.3bn
Moves to take down cyber-squatted domains reveals Fancy Bear hacking network, claims Microsoft
Intel claims 'world first' in artificial intelligence that can be plugged-in almost anywhere