The study examined the influence of fluorozirconic acid additions to the electrolyte on the growth rate and composition of porous anodic films formed on AA 2024-T3 alloy in sulphuric acid and tartaric-sulphuric acid electrolytes. A range of anodizing voltages, electrolyte temperatures, fluorozirconic acid concentrations and anodizing times was employed. High purity aluminium was employed as a reference material. Fluorozirconic acid increased the film growth rate, with a reducing influence as the temperature increased from 0 to 37 °C. The growth rate was enhanced by increased additions of fluorozirconic acid to the electrolyte, although chemical dissolution of the film was also accelerated. The films contained fluoride and sulphate ions from the electrolyte, with the fluoride concentrations decreasing with increasing temperature whereas the sulphate concentration was relatively unaffected. •Fluorozirconic acid (FZ) enhances film growth on aluminium/AA 2024 alloy in SA/TSA.•Effect increases with FZ concentration and decreases with acid temperature.•Fluoride and sulphate incorporated into film, but negligible zirconium species.•FZ enhances film dissolution, increasing with FZ concentration and temperature.•Negligible influence on corrosion protection due to absence of inhibiting species.