legally valid definition
legally valid means in this context that the solution applied to give or accept the mandate does not conflict with any existing piece of legislation be it national or European. However, as pointed out above, the fact that the way of authorisation was not against the law does not mean that in case of a claim by the payer that an unauthorised transaction has taken place, the creditor or the creditor PSP is in the position to prove that authorisation was given. In particular, in case of models with weak customer authentication this is often impossible in practice. In these cases the creditor and the creditor PSP have no other choice but to provide the refund to the payer as the burden of proof should clearly be with them.