The milestone comes three months after company announced 9,000 in August.
The company, which competes with more established providers such as Prestwood Truth and Voyant, reached 5,000 users 18 months ago.
Ray Adams, director and in-house Chartered Financial Planner, said he believed many users were opting for CashCalc because of its wide application in many financial advice situations.
He said: “Clearly people like CashCalc and the way we do things. We appear to have found a balance that suits many advice processes and this is testament to everyone involved, including all 10,000 account holders.”
To mark the latest milestone, CashCalc is inviting advisers to submit integrations they would like to see CashCalc develop.
Last week, the company announced what it called an “open integration” policy by offering to integrate with any other software or online system if it benefited “both the adviser and their clients.”
Mr Adams added: “As a practising financial adviser, I’m an advocate of using all the technologies available. So the more integrations that software providers can do with each other, the better in my opinion.”