Involved in the catabolism of oxalate and in the adapatation to low pH via the induction of the oxalate-dependent acid tolerance response (ATR). Catalyzes the transfer of the CoA moiety from formyl-CoA to oxalate (By similarity). formyl-CoA + oxalate = formate + oxalyl-CoA Metabolic intermediate degradation; oxalate degradation; CO(2) and formate from oxalate: step 1/2. Homodimer. Belongs to the CoA-transferase III family. Frc subfamily.