Caltex service stations will stop accepting AA Smartfuel discount cards from August 1.
In a letter sent out to subscribers this week, AA Smartfuel managing director Scott Fitchett said the organisation had ended its partnership with Caltex "due to competitive commercial reasons".
Fitchett added that AA Smartfuel would continue its partnership BP and announce new fuel partners by the end of July, taking the overall reach of the loyalty programme to 300 sites nationwide.
The discounts earned through the programme amounted to a record $132 million last year.
In addition to Caltex, petrol stations Z Energy, Gull, Mobil and Waitomo are also not involved in the programme.