HUNDREDS of Optus customers were left without reception due to congestion in phone towers.
An Optus spokesman commented on the interruptions after complaints from residents about phones cutting out.
The spokesman said interruptions lasted a couple of weeks and were due to too many people using the same signal.
"We've had planned outages for the past couple of weeks in Mundubbera and this was as a result of congestion in the Optus towers," the spokesman said.
"Once the problems were reported to Optus, we informed our engineering team and they fixed the problems so now it should be back to normal."
The spokesman said the problem could occur again if the signals became overloaded.
"The team creates reports on outages and that due to overuse in the area, problems with the reception occur," the spokesman said.
The Optus towers can hold up to 5000 customers but if there's too much activity, the towers experience service interruptions.