Scot FX will operate a white-label service on behalf of the chambers allowing thousands of members access to a dedicated system for foreign money transfers.
The Glasgow business said it has put plans to build up a dedicated retail presence "on the back burner" while it focused all its resource on getting the contract with Scottish Chambers agreed.
Scot FX – run by Direct Sharedeal founder Gordon Perry, former Ernst & Young partner David Tunstall and foreign exchange specialist David Hale – expects to start seeing the benefits from the tie-up by the end of this month.
Mr Perry said: "It opens us up to a considerably wider customer base and the potential is huge.
"The fact we can get to these companies through the chambers is great as it would take us years to do it through a different route.
"It has allowed us to accelerate plans for the business and to pick up a contract like this so early is fantastic."
Mr Perry has been travelling around Scotland meeting representatives from Chambers of Commerce to introduce the service and said the response had been "fantastic".
When Scot FX launched in spring last year Mr Perry had indicated he planned to build a significant consumer-facing retail presence and employ up to 30 people by the end of 2012. He admitted the business plan had changed since then.
He said: "We were always going to go after the SME market, but we have been concentrating so much on putting [the chambers deal] together we have not had the resources to concentrate on the retail side of things.
"[Business] has been slow as we have been concentrating so much on trying to seal the chambers contract that we haven't done as much in other areas that we could have. The chance was so good we had to do that.
"We still talk about retail regularly. Trying to get the right deal and the right rates is pretty difficult [in retail] so we decided to put it on the back burner.
"There is still the potential to add staff with the chambers contract. We will have to have business development people going out to meet the chambers around Scotland regularly.
"There's no way three people can handle it and we would need quality people to back us up."
Liz Cameron, Scottish Chambers chief executive, said she believes the Chambers FX service will help users reduce costs.
Mr Perry was one of four former Aitken Campbell directors who set up stockbroker Direct Sharedeal in Glasgow in 1999.
He stepped back from the firm towards the end of 2007 and it was acquired in 2008 by secretive former non-executive director Roland Witton who was based in Singapore.
Mr Tunstall worked in audit and corporate finance at Ernst & Young in Edinburgh, latterly in charge of around 70 staff, before becoming a consultant in 2009.