HGA Creative has also reported record-breaking sales of £2.5m for its financial year to 1 June 2014.
The agency has retained business from clients such as Lloyds Banking Group, Shop Direct and Brakes.
Managing director Michael Henderson said: "We have taken the time to celebrate what we have been told is a rare occurrence – a creative services business that lasts a quarter of a century in the ownership and management of its founders.
"We know that we have good levels of client satisfaction and retention – and are determined that more people know about the outstanding work and value that we deliver. From now on in we are going to shout a little more about what we are up to."
HGA Creative also works with Virgin Media, Kellogg’s and Phones 4u.