The taxpayer (seller) has a full range of primary and default (owner) rights in KSeF. Among other things, he has the authority to grant rights in KSeF, which, according to the Ministry of Finance, makes it possible, for example, to indicate entities that may, as buyers, issue invoices in the self-billing procedure.
The (self-billing) buyer authorized by the taxpayer (seller) has the right to self-invoice. Regarding the need to accept invoices issued in this way, it seems that KSeF – as a system that is, by design, generally available – may even simplify the matter. It will probably be sufficient if the applicable contract between the parties to the transaction (for self-billing) provides for the possibility of so-called “tacit acceptance.” Then, in a situation where the seller does not report irregularities to the buyer or does not refuse to accept invoices issued in KSeF (outside the system), it will be possible to assume that they have been accepted by them (without additional formalities).