The key law governing electronic signature was the Electronic Communication Act (2000) but this has been replaced by the UK eIDAS. Other regulations concerning electronic signature are common law and specific regulations. There are many contract-specific regulations that determine the method electronic signatures should be used in such cases, and if or not transactions can be executed via electronic signatures in such cases.
In parallel to EU law, and in contrast to other EU countries, the united kingdom legal system also encompasses a common-law element that for hundreds of years has been the premise for contract validity. A contract can be formed orally but must include certain elements to be legally enforceable including an offer, an acceptance, an intention to create legal relations, certainty over terms, and various other factors that the objects of the contract are legal.
England & Wales
Article 25 of UK eIDAS provides that an electronic signature can't be denied legal effectiveness solely due to its electronic nature.
The statute further provides that electronic signatures are admissible as evidence in legal proceedings. Section 7(1) of the ECA is similar to the admissibility provision in UK eIDAS:
“In any legal proceedings, an electronic signature incorporated into or logically related to a specific transmission or particular electronic data, and therefore the certification by any entity of such a signature, shall each be admissible in evidence in reference to any question on the authenticity of the communication or data or on the integrity of the communication or data."
The ECA 2000 doesn't expressly provide for the legal validity of electronic signatures. This lacuna has been filled by case law. However, the Law Commission, in a report in 2019, confirms that electronic signatures could be used to execute documents (and deeds) as long as the person signing the document intends to authenticate the transacting document; and any execution formalities are satisfie.
An electronic signature is therefore capable of satisfying required necessities under English law to be in writing and/or signed and/or made under hand.
cots case law is roughly similar to that in England & Wales. i.e. (that contracts can be formed based on a set of principles, similar to the English principles of intention and certainty). Scots Law recognises ‘consensus in idem’, which is a Latin maxim translating to “there must be an essential understanding between parties as to the terms of the contract”. The Requirements of Writing Act Scotland may restrict the use electronic signature where it otherwise is used in England & Wales. But The Electronic Documents (Scotland) Regulations 2014 does gives advanced electronic signatures validity within the context of the necessities of Writing Act.
Witnessing and attesting deeds
Deeds are a type of document with stricter formality requirements compared to other legal instruments. There are relatively few transactions which must be made by deed instead of by simple contract. A few examples of deeds include land transactions, mortgages, powers of attorney ato name a few. Deeds are also validly executed with an electronic signature by an individual and by an organization. The Law Commission, in a report in 2019, transparently signaled that if a deed must be witnessed, the witness must be “physically present” with the signatory during the signing of the deed in question. The witness must also the attest the signature. It is therefore possible now to execute a deed using an electronic signature under English law and satisfy any requirements of witnessing, attestation and delivery of the deed lawfully.