Electronic signatures have become the working default in UK accounting practice. Engagement letters, statutory accounts approvals, corporation tax computations, VAT registrations, and most internal documents are now signed and stored electronically as a matter of routine. The legal underpinning is well-established, but the edge cases still trip firms up - and the consequences of getting it wrong on the wrong document can be expensive.
This piece is a working senior-practitioner view of where e-signatures stand in 2026 from the perspective of a UK accounting firm. We cover the legal framework, what kinds of e-signature are recognised, the evidentiary weight of each, and the small but important list of documents where wet ink is still either required or strongly advisable.
The legal framework in the UK
The starting point in England and Wales is that an electronic signature is legally capable of being used to execute a document, and the law has been settled on this point for some time. The Electronic Communications Act 2000, the Law Commission's 2019 report on the electronic execution of documents (endorsed by the Lord Chancellor in 2020), and the retained EU eIDAS Regulation as it forms part of UK law together provide the framework.
In practical terms, this means that for most contractual and commercial documents - including the documents that pass between an accounting firm and its clients - an electronic signature is legally valid and admissible in evidence. The question is not whether it works, but which kind to use and how to keep the audit trail.
The three types of electronic signature under eIDAS
Retained eIDAS recognises three tiers of electronic signature:
- Simple Electronic Signature (SES) - any data attached to or logically associated with a document used by the signatory to sign. A typed name in the signature block of an email is technically an SES
- Advanced Electronic Signature (AES) - uniquely linked to the signatory, capable of identifying them, created under their sole control, and linked to the data such that any change is detectable
- Qualified Electronic Signature (QES) - an AES created by a qualified signature creation device and based on a qualified certificate, with the legal effect of a handwritten signature
Which tier is needed in practice
For the documents an accounting firm encounters in the ordinary course, an AES - provided by a reputable e-signature platform with identity verification, audit trail, and tamper-evident sealing - is more than sufficient. SES is technically valid in many cases but is harder to evidence if the signing is ever challenged. QES is required only in a small number of cross-border and regulated situations, most of which sit outside everyday UK accounting practice.
A defensible position is to standardise the firm on a single platform that delivers AES-level signing for all engagement letters, accounts approvals, and tax computations, and to reserve wet ink for the narrow list of documents that genuinely require it.
Documents that still require wet ink in 2026
Despite the breadth of e-signature acceptance, certain documents still require a wet signature in the UK or are most safely executed in that way. The current list includes:
- Statutory declarations and affidavits under the Statutory Declarations Act 1835, which require a personal appearance before an authorised official
- Wills under the Wills Act 1837, where the witnessing requirements have not been satisfactorily met by purely electronic processes
- Lasting Powers of Attorney as registered with the Office of the Public Guardian, which require specific witnessing
- Certain documents required to be filed with HM Land Registry, where the rules permit only narrow categories of electronic signature
- Documents intended to be used overseas in jurisdictions that do not recognise UK electronic signatures
Documents that look formal but accept e-signatures
A number of documents in accounting practice look as though they should require wet ink but do not. These include:
- Engagement letters under the ICAEW or ACCA professional standards
- Statutory accounts approval by the directors for filing under the Companies Act 2006
- Corporation tax computations and supporting working papers
- VAT registration applications and FTA EmaraTax submissions
- PAYE and self-assessment authorisations to HMRC, where the agent authorisation flow accepts electronic confirmation
- Shareholder resolutions, subject to the company's articles permitting written or electronic execution
Audit trail and evidentiary weight
In the event of a dispute, the evidentiary value of an electronic signature depends not on the signature itself but on the audit trail behind it. A defensible audit trail captures the signatory's identity verification, the IP address and device used, the time of signing, the version of the document signed, and a tamper-evident seal that detects any subsequent change to the file.
Reputable e-signature platforms produce this audit trail automatically and make it available as a certificate attached to the executed document. For UK accounting firms, the discipline is to store both the executed document and its audit trail certificate against the client record. Storing only the PDF is a partial file.
Cross-border considerations
For UK firms with UAE clients or vice versa, the cross-border position is broadly comparable. The UAE Electronic Transactions and Trust Services Law (Federal Decree-Law No. 46 of 2021) and the related Cabinet Decision provide for electronic signatures and trust services, and the UAE recognises both standard and reliable electronic signatures. Documents intended to be relied on in either jurisdiction can generally be signed electronically using a recognised platform, with the wet-ink exceptions broadly mirroring the UK list.
Where a document is intended to be relied on in a third jurisdiction, check the position of that jurisdiction before assuming an electronic signature will be accepted. A small number of jurisdictions continue to require wet ink for certain corporate and real estate documents.
Internal firm-side execution
A separate question is the firm's own internal sign-off. Working paper reviews, partner approvals, quality control sign-offs, and internal authorisation chains can all be evidenced through the practice management platform without paper. The standard to meet is the same as for client-facing signatures - a clear identity, a clear timestamp, and tamper-evident storage of what was signed.
For ICAEW-regulated firms, the audit and quality control standards require evidence of partner review and engagement quality control review where applicable. Electronic sign-off captured through a recognised platform meets that evidentiary requirement and is easier to produce on inspection than a paper file.
A working firm policy
A workable firm policy on signatures in 2026 has three components. First, default to electronic signing for all engagement letters, accounts approvals, tax computations, and internal reviews through a single approved platform. Second, maintain a short, written list of documents that still require wet ink or notarisation, and a process for those exceptions. Third, store both the executed document and its audit trail certificate against the client record in the practice management system.
A policy that lives in writing and is acknowledged annually by every partner and senior is materially easier to defend than an undocumented working practice.
How Accupe helps
Accupe includes a built-in e-signature module as part of the practice management platform, with identity verification, tamper-evident sealing, audit trail certificates, and storage of the executed document against the client record. Engagement letters, accounts approvals, tax computations, and internal sign-offs all sit in one place alongside the Smart Boards, AML/KYC screening via OpenSanctions, encrypted client messaging, and AI document analysis with source citation. There is no separate DocuSign or Adobe Sign subscription to manage. Per-firm pricing from £20/month.