Complaints about NBN services have more than doubled since last year, with internet problems outnumbering mobile phone complaints for the first time.

The Telecommunications Industry Ombudsman (TIO) 2016/17 annual report revealed that more than 27,100 complaints were lodged specifically about the National Broadband Network (NBN) in the last financial year.

This was a 159 per cent increase compared to the previous year’s 10,400 complaints.

TIO ombudsman Judi Jones said the surge in NBN-related grievances was a “concerning trend”.

“Complaints about services delivered over the NBN more than doubled, and while this is somewhat to be expected given the accelerating rollout, the increase is a cause for concern,” Ms Jones said.

“For the first time, complaints about internet services are now higher than complaints about mobile phones.”

Internet connection delays were the most commonly reported problems (7035 complaints), followed by internet and landline faults for services delivered over the network.

NBN-related complaints accounted for about 17 per cent of the total 158,016 telecommunications complaints from across the country over the past financial year.

Overall, internet complaints increased by 64 per cent, with a 30 per cent rise in both landline and mobile phone problems.

About 90 per cent of grievances were from residential consumers, while almost 12 per cent came from small businesses.

“The picture the complaints show is we are frustrated when we cannot rely on technology to stay connected, to be informed, and to do business,” Ms Jones said.

“Sharing high-quality videos immediately, holding an online meeting or watching Netflix on the way home, is now the norm and part of our daily routine.”

Complaints from customers of telcos Telstra, Optus, TPG and Vodaphone rose by 43.5, 31.2, 44.9 and 37.5 per cent respectively.

Following the end of the financial year, Australian consumer watchdog ACCC in July announced it was investigating “some” of the big four telecommunications service providers over allegedly “misleading” NBN internet speed claims.

NBN Co provided a statement acknowledging that the TIO’s reported increase in NBN complaints was “regrettable”.

It has launched a number of initiatives aimed at minimising the problems encountered by some consumers as they move onto the NBN including in-house field worker training facilities, improved fault detection and a national awareness campaign.

“We are working with retail service providers and industry as a priority to improve these figures and the overall experience for consumers,” the statement read.

“Overall TIO complaints about services delivered over the NBN network represent about 1 per cent of the number of activated premises.”

It added that the report did not distinguish which complaints were NBN’s responsibility and those that rested with the service provider.

Paul Brookes, chair of advocacy group Internet Australia, said the “dramatic surge” in complaints needed to be “urgently addressed”.

He called for the Ombudsman to be given the power to investigate wholesale internet suppliers, not just retail providers.

“This is urgent and overdue, and would help hold wholesale network providers to account when their actions impact an end-user customer.”