1. Member States shall ensure that a payment transaction is considered to be authorised only if the payer has given consent to execute the payment transaction. A payment transaction may be authorised by the payer prior to or, if agreed between the payer and his payment service provider, after the execution of the payment transaction.
2. Consent to execute a payment transaction or a series of payment transactions shall be given in the form agreed between the payer and his payment service provider.
In the absence of such consent, a payment transaction shall be considered to be unauthorised.
3. Consent may be withdrawn by the payer at any time, but no later than the point in time of irrevocability under Article 66. Consent to execute a series of payment transactions may also be withdrawn with the effect that any future payment transaction is to be considered as unauthorised.
4. The procedure for giving consent shall be agreed between the payer and the payment service provider.