A method of digitally executing a document to be authorised by a plurality of entities that together make up a signature-approval chain, wherein there is a required authorisation for each of the plurality of entities, the method comprising: digitally communicating a first authorisation request to a first entity in the signature-approval chain; sequentially digitally communicating a respective authorisation request to each remaining entity (150, 160, 170) in the signature-approval chain in turn after receiving authorisation data from a previous entity in the signature-approval chain complying with the required authorisation of the previous entity; and after receiving from each of the plurality of entities authorisation data complying with their respective requested authorisation, generating an executed document, wherein: each document authorisation request comprises the document and a request for the required authorisation corresponding to the entity to which the document authorisation request is directed, and wherein the required authorisation for at least two of the plurality of entities comprises a requirement for a signature from the entity, and wherein the executed document comprises the document and at least two signatures corresponding to the respective at least two entities having a required authorisation comprising a requirement for a signature, and wherein each of the at least two signatures corresponding to the respective at least two entities are applied to the document only at the time of generating the executed document. digitally communicating a first authorisation request to a first entity in the signature-approval chain; sequentially digitally communicating a respective authorisation request to each remaining entity (150, 160, 170) in the signature-approval chain in turn after receiving authorisation data from a previous entity in the signature-approval chain complying with the required authorisation of the previous entity; and after receiving from each of the plurality of entities authorisation data complying with their respective requested authorisation, generating an executed document, wherein: each document authorisation request comprises the document and a request for the required authorisation corresponding to the entity to which the document authorisation request is directed, and wherein the required authorisation for at least two of the plurality of entities comprises a requirement for a signature from the entity, and wherein the executed document comprises the document and at least two signatures corresponding to the respective at least two entities having a required authorisation comprising a requirement for a signature, and wherein each of the at least two signatures corresponding to the respective at least two entities are applied to the document only at the time of generating the executed document. each document authorisation request comprises the document and a request for the required authorisation corresponding to the entity to which the document authorisation request is directed, and wherein the required authorisation for at least two of the plurality of entities comprises a requirement for a signature from the entity, and wherein the executed document comprises the document and at least two signatures corresponding to the respective at least two entities having a required authorisation comprising a requirement for a signature, and wherein each of the at least two signatures corresponding to the respective at least two entities are applied to the document only at the time of generating the executed document.