How valid is a digitally signed contract?

Question

José Manuel Alburquerque · Accepted Answer

Just as valid as a contract signed on paper, because the law gives electronic contracts full effect and does not require any particular type of signature for a contract to be valid. What changes with the type of electronic signature is how easy it is to prove if the other party denies having signed. A qualified signature, such as one made with the Spanish electronic identity card (“DNI electrónico”), is presumed to be genuine and anyone who denies it has to prove otherwise. With signatures that do not use any qualified service, such as those of many platforms that sign by email or SMS, if the other party denies the signature, it is the person relying on the contract who has to prove it. The three types of signature A European regulation, which applies in the same way throughout Spain, distinguishes three types of electronic signature: A simple signature, which is any electronic data used to sign, such as typing your name at the end of an email or pasting in the image of a scanned signature. An advanced signature, which is uniquely linked to the signatory, allows them to be identified, is created using means under their sole control and shows whether the document was altered afterwards. A qualified signature, which is an advanced signature made with a qualified certificate and with a signature creation device that is also qualified, such as the chip in the electronic identity card. A certificate is qualified when it meets the requirements of the regulation and is issued by a provider included in the official list of qualified providers. No signature can be denied legal effect merely because it is electronic or because it is not qualified. A qualified signature also has the same effect as a handwritten one. The same rules apply in Catalonia as in the rest of Spain, because they are all European or national rules. If the other party denies having signed The “Ley de Enjuiciamiento Civil”, Spain's Civil Procedure Act, allocates the burden of proof according to whether or not a qualified service was used, such as those behind a qualified signature: With a qualified signature, the document is presumed to be genuine and unaltered if the provider of the service was on the official list of qualified providers. Whoever denies it has to carry out the verification. If the result goes against them, they pay the costs of that verification and, if the judge considers their challenge reckless, the judge may also fine them between 300 and 1.200 euros. With a simple signature, or with an advanced one for which no qualified service was used, the person relying on the document has to prove that it is genuine, usually with an expert report. If this remains unclear, the judge weighs the document together with the other evidence. That is why the difference between one type of signature and another lies not in the validity of the contract but in how easy it is to prove. What you should keep If you sign through a platform, keep the evidence report (audit trail) or signature certificate that it usually provides at the end, which is the document summarising how the signature was made. It records the emails, the date and time, the codes sent by SMS and the IP address, which identifies the connection from which the document was signed. This is what makes it possible to prove a simple or advanced signature if someone disputes it. Also keep the signed file, because the electronic signature is in the file and not in a printed copy. An electronic signature is no substitute for a deed before a notary where the law requires one, as for the gift of a flat or the creation of a mortgage.