A report by the Telecommunications Industry Ombudsman shows that ACT residents made 3,203 complaints during the 2011-2012 year about issues such as mobile phone data plans and global roaming charges.

The rate of complaints in the ACT was 8.9 complaints per 1000 people, making us the third most concerned state or territory.

Victoria, with 56,785 complaints, had the highest ratio with 10.6 complaints per 1000 people. South Australia was next with 15,936 complaints, at a rate of 9.9. Northern Territorians were the least likely to complain, lodging just 1,169 for a rate of 5.5 per 1000 people.

Inner city Melbournians had the highest complaint rates per postcode, with people in Melbourne City complaining at a rate of 24.4 per 1000. Docklands was next worst with 22.2.

In Canberra, Amaroo's post code recorded the most complaints at 10.6. The top complaints were about coverage, disputed usage charges and the total bill amount.

The rest of the top 10 for the ACT were: Braddon (9.9), Ngunnawal (9.6), Kambah (9.5), Isabella Plains (9.3), Melba (8.9), Monash (8.7), Dickson (8.6), Belconnen (8.6) and Conder (8.4).

Nationally the TIO received 193,702 new complaints in 2011-12, a drop of two per cent on the previous year.

Ombudsman Simon Cohen said telcos were improving their customer service.

"There has been a significant trend, since April 2012, of reduced complaints, with the last quarter being the quietest for almost two year," Mr Cohen said.

The complaint areas that jumped the most were financial overcommitment because of poor spend management tools, which doubted to 15,752 complaints, and disputed internet usage charges, which increased by 150 per cent to 10,556 complaints.