Vodafone and Spark have a long way to go before their customers feel satisfied with their service, according to Consumer NZ's latest internet service provider (ISP) survey. Both rated below average in nearly every category.

The two companies' performance had also dropped since the last survey in 2013.

Overall satisfaction with ISPs was 68%, down from 74%.

Consumer NZ says a key measure of an ISP's performance is the reliability of the connection and speed. Sue Chetwin, Consumer NZ CEO, says the survey results showed a decline in reliability ratings.

Disconnections and dropouts remained problems with 57% of survey respondents saying they occasionally had problems and 15% saying they happened regularly.

Most people also had problems with speed - only 20% said they had never had slower-than-expected speed. This was down from 22% in the 2013 survey.

The top three performers, with more than 90% satisfaction, were Actrix, Inspire Net and Snap. Consumer NZ says these companies have been among the top five performers for the past three years.

Showing improvement were Slingshot (up 9%) and Orcon (up 4%) in overall satisfaction.

Around 9% of respondents had switched to ultra-fast broadband, and were more likely to be satisfied or very satisfied (73 %) with connection speed. UFB customers were also more likely to be satisfied they were getting value for money. But ratings for this measure weren't high; just 58 % of UFB customers thought they were getting value for money.

Chetwin says recent price hikes were unlikely to improve value for money ratings. Spark and Vodafone have both raised rates and smaller providers are expected to follow.

For the third year running, 2degrees was the standout performer in terms of mobile service providers, according to Consumer NZ. It says 87% of members rated its services as good or very good. It was up 4% on the last survey. Vodafone and Spark both scored around 70% overall satisfaction.

Consumer members on pre-pay plans were more likely to be satisfied their provider was delivering value for money – 61% of pre-pay customers were either satisfied or very satisfied they were getting bang for their buck compared with 49 % on fixed-term contracts.

2degrees and Inspire Net have gained Consumer Trusted accreditation. This means they have been assessed against the Consumer NZ Code of Conduct and met the criteria to be awarded accreditation. Customer service is one of the key principles in the accreditation criteria.

A total of 10,742 Consumer NZ members took part in the ISP satisfaction survey; 10,424 members participated in the mobile satisfaction survey.