Budget has acquired Abercorn Insurance Brokers as part of its quest to buy 40 brokers by the end of the year.
All six staff and 1,800 policies - 80% in the motor trade - have been transferred to the Budget's Paisley offices.
Richard Elliot, Abercorn's former managing director, said: "It's been a family-owned business for 41 years, but I couldn't see it lasting long term unless it became part of an intermediary.
"I see a rush of brokers seeking to sell up in 12 months' time."
Budget retail network director Matthew Donaldson said: "Gaining these additional policies is a fantastic addition to the current business we have in Scotland."
Budget has a target of an extra 100,000 policies by June next year.