Kent Reliance Building Society has been named best cash ISA provider.

The Chatham-based mutual, the UK’s fastest growing building society, scooped the accolade for the second year in a row.

Last year, it had to share the honours in a joint award to Nationwide Building Society, but this time around readers of What Investment magazine voted Kent Reliance into undisputed top spot.

Chief executive Mike Lazenby said: "We have appeared regularly in the best performing ISA tables for the past four years and MoneyFacts has recognised us as the most consistent ISA provider in its last 18 month survey.

"This is about being fair, open and transparent. Everyone in the ISA market talks about transparency, but very few actually deliver. It means you don’t have to keep looking over your shoulder to make sure that your ISA provider isn’t dropping its rates. We don’t do that.

"Equally, if someone wants to change their ISA provider it can take months. If you want to move from us, we guarantee to transfer within seven days, although we normally make such transfers on the day a request is received.

"Not surprisingly, a large number of the people who have moved away from us to get a better short term rate come back, because they recognise that we are very consistent at what we do."

Kent Reliance is the 19th largest building society in the UK with assets of around £2.1 billion. It has expanded rapidly by reducing its costs by outsourcing processing work to India, offering well-regarded savings products, and expanding its home loan operations in the Channel Islands.

The current rate of its Direct ISA is 5.76 per cent.