The Fuelcard People is a "strategic fuel-cards partner" to help members keep a lid on vehicle running costs, said association chairman Kelvin Harbutt.
"Our members can now gain savings from lower fuel costs and reduced administrative workloads," he said. "The Fuelcard People will offer savings, service and security."
Fixed weekly pricing for diesel, petrol or both was typically 2p to 3p per litre below national average pump prices, and more than 10p less than motorway prices, he said.
The Fuelcard People associate account manager Steve Gale said: "Depending on the fuel card, you can refuel at up to 1,500 filling stations nationwide."
Cards are valid at BP, Esso, Shell, Texaco, Q8, Jet, Gulf, Spot, Murco, Morrisons, Somerfield and Moto stations, and on Keyfuels Diesel Direct and ReD networks.
The Fuelcard People is an independent agent of UK business-fleet, discount diesel and petrol fuel cards for cars, vans, LCVs, lorries, HGVs and minibuses.