Under the tie-up, small business customers of RBS and its NatWest arm will be offered free access to FreeAgent’s service, which has been piloted by the state-backed lender since October.
FreeAgent, which employs more than 100 people, develops accounting software aimed at the UK’s five million “micro-businesses”.
It said the deal with the banking group would cater for all of its small business customers’ finance requirements, “from timeslips to tax returns and quality after-sales support”.
The company floated on London’s Alternative Investment Market in November, in a move that valued the firm at more than £34 million.
Marcelino Castrillo, managing director of business and private banking at RBS, said: “The way customers want to bank with us is constantly changing, so it is important for us to innovate.
“From over 30 vendor proposals we chose FreeAgent because of their willingness to collaborate with us and shape a proposition that really works for our customers, as well as the capability of their platform.”
He added: “The feedback on FreeAgent’s platform speaks for itself, and when we piloted FreeAgent with our customers the majority said they would recommend us if we were to offer the service in future. This sort of endorsement is hard to come by so I’m very excited to see where this partnership can take us.”
The service will be offered free to RBS’ business account customers who agree to share data, with licences paid to FreeAgent directly by the bank.
FreeAgent chief executive and co-founder Ed Molyneux said: “Given that our relationship with RBS only started in October, we do not expect a material revenue contribution from licences sold under the agreement for the year ending 31 March 2017 and we expect an accurate picture of the level of take-up by RBS clients to emerge only once we have several months of operational data at our disposal.
“However, we are naturally excited about the potential for this new agreement, particularly once our services are made available to RBS’ back-book in the second half of 2017.”