Advisers rated overall satisfaction with lenders at 82% in the survey by financial research company Smart Money People.
Barclays and Metro Bank fared worst out of the largest lenders, according to the 400 brokers questioned.
Building societies overall performed best among brokers, with the sector outperforming banks.
Business development managers and underwriting of mutals were scored particularly highly.
High proc fees but poor service
It was found that a small group of lenders with higher than average procuration fees tend to have average or below average service levels of broker satisfaction.
Specialist lenders scored well on product and lending, but process improvements are required for many of these providers, the feedback suggested.
There was no specialist lender that scored above 75% under the factors examined.
Lifetime lenders processes are most in need of an upgrade on process, with valuations, underwriting and ease of application standing out as the three key issues for brokers.
More 2 life is the UK’s highest rated lifetime lender.
Speed to completion, online portal, criteria, underwriting and customer service dominated feedback in the survey.
Mike Fotis, founder of Smart Money People said: “Brokers told us clearly that frustrations with lenders’ underwriting, customer service, speed to completion and clarity of criteria rankled them most.
“It will be interesting to see if lenders at the bottom of our league table are able to improve when we repeat the survey again in 2019. The customer reviews we already collect will also help us to track this.”