In many companies, the introduction of eSignatures does not fail because of the technology, but because of uncertainty regarding legal validity, verifiability and compliance. Specialist departments want to speed up processes, approve documents more quickly and sign contracts digitally. At the same time, Legal, Compliance, Data Protection, Procurement and C-Level need to ensure that the chosen solution is regulatory compliant.

This is precisely where a backlog of decisions often arises. Many solutions advertise with terms such as “legally compliant” or “certified” without making it transparent how these legal and compliance requirements are actually implemented. This makes evaluation more difficult. For companies, it is not enough for a solution to technically enable signatures. It must also be embedded in a robust, traceable process.

The key question is therefore: Is a digital signature legally valid in principle – and what do companies need to bear in mind? This article answers precisely this question at a strategic level. Not as a technical guide and not as a detailed legal interpretation, but as an orientation aid for a well-founded assessment.

When a digital signature is legally valid

Is an electronic signature automatically legally valid?

No, not every digital signature is automatically legally valid.

In practice, for example, there is a persistent assumption that simply inserting a photo of your own handwritten signature into a document is sufficient. This shows exactly how quickly the term “digital signature” is misunderstood. A seemingly simple visual image of a signature is not automatically legally binding.

Whether a digital signature is legally valid depends rather on the specific use case, on regulatory requirements, and on the chosen signature level. It is precisely at this point that uncertainty arises in many companies, because often there is no clear classification as to which signature level is required or appropriate in which context: Is it about the simple (SES), advanced (AES), or qualified (QES) signature level? A brief classification upfront: In principle, only the qualified electronic signature is an example of equivalent legal effect, equivalent to a handwritten signature.

SES and AES certainly have their justification – but in other use cases and with different evidentiary value. Which level is appropriate or required in which context is something we deliberately do not examine in detail in this article. An in-depth discussion of SES, AES, and QES can be found here.

Another point is crucial here: legal certainty is not a generalised product feature. It does not arise simply because a provider emphasises a certain function or feature. Legal certainty is the result of a structured assessment of the specific process.

What legal certainty and compliance depend on

In order for a digital signature to be used in a regulatory viable manner, several factors must fit together. The decisive factor is the interplay of:

  • Signature level
  • Identification
  • Traceability
  • technical realisation

These factors should not be considered in isolation. Only their combination determines whether a signature process is reliable in the respective context. It is not the individual tool that creates legal certainty, but the documented overall process. This is particularly important for internal approvals.

Why compliance is more than just a label

Legal and Procurement not only evaluate functions, but also the question of whether a process can be set up in a comprehensible, auditable and governance-capable manner. This is precisely why compliance is more than just a label.

A solution can be technically strong and still not automatically fulfil the requirements of a company. Conversely, a clean process logic can help to reduce legal risks and increase decision-making capability.

For companies, this means that the question of a legally compliant digital signature can only be answered in a meaningful way if the entire signature process is considered, not just the software.

Legally compliant digital signature: checklist for companies

Before introducing or changing an eSignature solution, companies should clarify a few basic questions. Working through the relevant checklist helps to reduce legal uncertainty and create the basis for a well-founded legal sign-off.

Important test questions

  1. Which document type is available?
  2. What is the required evidential value?
  3. What identification is required?
  4. What data protection and audit requirements exist?
  5. Which internal authorisations are required?

These questions create structure in the evaluation. They help shift the focus from a mere tool selection to a legally valid standard process.

In this context, so-called Trust Service Providers (TSPs) also play an important role – that is, certified entities that issue regulatorily recognized trust services such as qualified signatures or timestamps. In the EU and eIDAS context, they are referred to as Trust Service Providers, while under Swiss law (ZertES) they are called recognized providers of certification services. At their core, the same role is meant, but the regulatory foundations differ.

In the field of advanced electronic signatures, for example, there are providers who offer their own solutions for this, and there are solutions that integrate different VDAs. Of course, this also applies to other signature levels. Other audited bodies may also become relevant, for example in the area of identity verification.

This shows that a resilient signature process often consists of several components that have to interact properly from a regulatory perspective. If you want to build these components completely yourself, you face a correspondingly high level of effort.

Regulatory frame of reference

As soon as companies operate internationally or in regulated environments, the regulatory frame of reference plays an important role.

In the European context, the categorisation around the eIDAS signature is particularly relevant. In the Swiss context, ZERTES, i.e. the “Federal Act on Certification Services in the Field of Electronic Signatures and Other Applications of Digital Certificates”, can also be included in the assessment.

In the context of VDAs, it is important to mention that – depending on the specific provider – they can cover only ZERTES, only eIDAS or both. This can also only be meaningfully evaluated if it is clear what purpose the respective solution serves and how the entire signature process is documented.

Why architecture and digital sovereignty are only supportive

Architecture, data sovereignty and secure processes support legal certainty. However, they are no substitute for a regulatory assessment.

For many companies, questions of digital sovereignty are an important part of the decision-making process. This is particularly true when sensitive documents are processed or there are high governance and data protection requirements. In such cases, infrastructure components such as a white label solution or concepts such as zero document knowledge can be relevant.

The following link provides more insights into Zero Document Knowledge Workflows and end-to-end encryption.

However, it is important to categorise them clearly: these factors strengthen control, traceability and trust in the technical architecture. The actual legal validity of a digital signature does not automatically result from this. Architecture can support legal certainty, but it cannot replace it.

Conclusion: Legal certainty comes from clear decision-making logic

Electronic signatures can be legally valid, but they are not automatically so. Whether it is regulatory viable depends on the use case, the requirements for identification and verifiability, the selected signature level and the technical implementation of the overall process.

For companies, this means that legal certainty is not created by advertising claims or product labelling, but by a clear decision-making logic. A structured assessment of regulatory requirements reduces risks, provides orientation for legal and procurement and speeds up internal approvals.

The next sensible step is therefore to evaluate the signature levels in a structured manner:

Which signature level makes your digital signature in the PDF legally valid? View the decision logic for SES, AES and QES now: eSignature standards/types/levels