The days of ‘wet’ signatures may be numbered, sending documents by post to get original ink signatures is slow process, times are changing.
The UK government divides electronic signature into three groups:
- Simple electronic signatures – these include scanned signatures and tick box declarations
- Advanced electronic signatures – can identify the user, is unique to them, is under the sole control of the user and is attached to a document in a way that it becomes invalidated if the contents are changed
- Qualified electronic signatures – an advanced electronic signature with a digital certificate encrypted by a secure signature creation device eg Smart Card
Here is the full government guidance https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/356786/bis-14-1072-electronic-signatures-guide.pdf
I am a big fan of Adobe who say….
Adobe e-signatures are trusted, legally valid and enforceable in industrialized countries around the world. Our eSign services comply with industry security standards including SOC 2 Type 2, ISO 27001, PCI and HIPAA.
The most quoted case law is Golden Ocean Group Ltd v Salgaocar Mining Industries PVT Ltd and Another  EWCA Civ 265, in the case a guarantee was negotiated over several weeks via e mail and although no formal guarantee document was signed the High Court accepted that the e mails could be accepted as evidence of agreement and signature.
Electronic signatures save time and make life easier for everyone.