The Consilium Accountancy Group head office, on West George Street in Glasgow, is now home to 23 people with two further employees to be added soon.
As well as picking up clients from across the country the firm is closing in on becoming an accredited training centre for the Institute of Chartered Accountants of Scotland (ICAS).
The six Consilium partners - Charles Burton, Tom Arbuckle, John Blair, Raymond Clarke, David Holt and James Goodman - resigned from RSM Tenon in August last year but faced having to wait until May this year before they could work again as they had restrictive covenants with the business.
But following the acquisition of RSM Tenon out of administration by Baker Tilly the Court of Session ruled those covenants were no longer applicable.
Mr Burton, formerly managing partner in RSM Tenon's Glasgow office, said Consilium appeared to have generated a lot of good will from other professionals across the city, which has led to it winning work from local bankers and lawyers.
He said: "The support we have received has been fantastic and we have had a number of referrals.
"We have also got business from clients which wouldn't previously have considered us but they see us as a better fit for their business now as an independent.
"There is perhaps an element of good timing to setting up the firm at this time as the economy appears to be improving again."
Asked whether further hiring could be on the cards Mr Burton said: "We have had a busy three months and we aim to take a breath before continuing.
"It is a good start and we think there is room in the market for us."
The firm signalled it was active across a number of industry sectors but is mainly focused on owner managed business.
The geographic spread of the client base is said to run from the north of Scotland down into Dumfries and Galloway while a recent due diligence instruction would be the firm's first piece of work in England.
Mr Blair, a corporate finance specialist, said: "We have a good pipeline of ongoing and potential deals over the next few months.
"From our point of view the banks are definitely lending more and that is helping to generate more activity."
The firm would not reveal any potential fee targets for its first year of trading.
However Mr Holt, also a corporate finance specialist, said: "We are aiming for steady and sustainable growth. We don't want to chase turnover."
Mr Arbuckle pointed out he has previously sold his own business, bought Mr Burton's business and gone through a start-up phase.
He said: "Not many accountants start their own firm.
"It gives us another point of difference."
Mr Blair said the firm would consider using its own experience to advise other start-ups but acknowledged that businesses at that stage were unlikely to use much of their funds to hire accountants.
RSM Tenon fell into administration last year after struggling under an £80 million debt to Lloyds Banking Group.
The Scottish practice, which employed around 240 across the country, was thought to be profitable and had a turnover in the region of £14m.
Eight former partners from the RSM Tenon office in Edinburgh joined Mazars following the takeover by Baker Tilly.