The Dublin software company, Baydon Ltd, has signed a $100,000 (£68,054) contract with the US Internal Revenue Service (IRS) for use of its Assistware software.
The small company hopes to agree further contracts with the IRS which could amount to more than £1 million over the next five years.
Assistware is a form of performance software which makes it easier for people to understand and use IT systems. The IRS in the US employs 750,000 people and is one of the largest government organisations in the world.