(17)PSUs are very sensitive to the level of charges for substitutable payment methods. The level of charges can therefore steer them towards or away from a given payment method. In national markets where higher transaction-level charges for instant credit transfers in euro have been applied, when compared to charges for other credit transfers in euro, the uptake of instant credit transfers is low. That has prevented the attainment of the critical mass of instant credit transfers in euro that is necessary to realise the full network effects for both PSPs and PSUs. Therefore, all types of charges applied to payers and payees for the execution of instant credit transfers in euro, including per-transaction charges or lump-sum charges, should not exceed such charges applied to the same PSU for corresponding types of other credit transfers in euro. It would be undesirable that PSPs circumvent the aim of that requirement. When identifying corresponding types of credit transfers, it should be possible to use criteria including the payment initiation channel or the payment instrument used to initiate the payment, customer status, and additional features or services.