Paddy Power and MoneySuperMarket.com radio ads have been banned for voicing the terms and conditions so quickly listeners were unable to understand them.
Complainants said both ads, heard in December, were misleading because the terms and conditions were spoken so quickly and at such low volume they were unintelligible.
Paddy Power said its ad featured its Bet Builder promotion which offered users a free bet up to £10 if one leg of an accumulator bet was unsuccessful.