Electronic signature for business – how it works, why it matters, and what happens without it

Digital transformation is no longer just a trend — it’s a business necessity. And at the heart of it, especially for large enterprises, is the electronic signature. Without it, there’s no way to build an automated, scalable, and controlled document workflow within a modern corporate structure. Businesses simply don’t have time for slow approvals, lost paperwork, or human error.

What is an electronic signature?

An electronic signature is a tool that confirms a specific individual has signed a specific document. It’s not just a scanned image or a handwritten signature copy — it’s a secure digital marker that requires a private key and verified identity to be created.

Why does a business need an electronic signature?

Large companies handle thousands of documents every day. If signing each of them requires printing, mailing, or manual approvals, it slows down critical steps in the document workflow.

Without a qualified electronic signature (QES), businesses face limitations — or even complete inability — to:

• Sign legally binding contracts online
• Participate in tenders (like Prozorro)
• Submit reports to tax authorities or interact with the State Tax Service
• Integrate document workflows into modern ERP/CRM systems
• Ensure data protection in line with compliance standards
• Collaborate effectively with distributed teams and external partners

In practice, the absence of QES halts digital transformation. It leads to approval chaos, delays in signing important documents, and increased legal risks. Paper-based and digital processes start running in parallel, making control, auditing, and scaling far more difficult.

Three types of electronic signatures – what you need to know

To understand the role of electronic signatures, it’s essential to distinguish between the three main types:

1. Simple electronic signature (SES) – This is the most basic form, with no cryptographic protection. It can be as simple as a checkbox or a code received via SMS. It’s suitable for confirming actions within digital services but not for legally binding documents.
2. Advanced electronic signature (AdES) – A more secure option, generated using a digital key. It offers a higher level of protection and can be used in internal document workflows if both parties agree to it.
3. Qualified electronic signature (QES) – This is the highest level of electronic signature. It carries full legal weight, is equivalent to a handwritten signature, and can only be issued by accredited trust service providers. It must be created using a certified signing device.

QES is essential for large businesses — without it, you can’t work with tax authorities, courts, public procurement systems, or banks. It can be stored on a secure USB token, as a digital file, or in the cloud with two-factor authentication. The most efficient approach is when the signature is integrated directly into enterprise systems like Microsoft 365, ERP, ECM, or CRM — making it part of the workflow, not a separate manual step.

QES for individuals and legal entities

An electronic signature can be issued to both individuals and legal entities. A qualified electronic signature (QES) for an individual is often used for HR-related documents — such as vacation requests, hiring or termination orders, and electronic employment contracts.

In contrast, a QES issued to a legal entity includes not only the signer’s personal details, but also the company’s identifier (EDRPOU code) and the official position of the signer. This distinction is critical for contracts, acts, and tax reporting — any case where it’s necessary to confirm that the signer is acting as an authorized representative of the organization, not just as an individual.

How electronic signatures work

An electronic signature performs several critical functions within digital document workflows:

• Authentication – ensures the document was genuinely created and signed by the intended individual.
• Integrity – if the document is altered after signing, the system detects it and invalidates the signature.
• Legal validation – the signature is timestamped and holds full legal weight (in the case of a QES).
• Audit trail – it’s possible to trace who signed the document, when, and which document it was.

From a technical perspective, electronic signatures are based on cryptography. But you don’t need to know the details of asymmetric encryption — only the core idea:

1. You receive a private key (on a USB token, flash drive, or in the cloud).
2. When you sign a document, your key generates a unique digital fingerprint.
3. Anyone can verify the signature using the corresponding public key to confirm whether the document was altered after signing and who signed it.

This process guarantees that:

• The signature was created by the right person.
• The document has not been modified after signing.
• It holds legal validity (in the case of QES).
• The exact date and time of signing are securely recorded.

One of the most secure ways to store your key is on a USB token — a physical device that only works with a password, prevents key duplication, and provides the highest level of security. An alternative is cloud-based storage with two-factor authentication.

Integrating QES into business systems isn’t automatic — it requires dedicated solutions. In reality, most companies lack end-to-end automation of signing processes across all their systems. That’s why platforms like e‑Docs are gaining traction: they enable centralized control over documents, approvals, and signatures — fully compliant with legislation and integrated with popular ERP and CRM systems via API.

Where and how to get an electronic signature

In Ukraine, electronic signature services are available in various formats — from free e-signatures via the Diia app to qualified electronic signatures (QES) stored on USB tokens or in secure cloud environments.

There is an official list of accredited certification centers (ACCs) authorized to issue qualified signatures.

Some of the most widely used platforms include:

• Diia.Signature (Ministry of Digital Transformation)
• PrivatBank
• ACC of the State Tax Service (STS)
• Vchasno
• Key Certification Center (including Uakey, DepositSign, and others)

Electronic signatures typically remain valid for 1 to 2 years, after which the certificate must be renewed. In some cases (e.g. via the Diia app), e-signatures can be obtained for free, though with limited functionality.

Once you receive your signature, it’s important to integrate it into your company’s approval workflows, access control mechanisms, and archiving systems. When e-signatures are embedded in the process, they accelerate decision-making. When treated as an external step, they slow everything down.

What you need to get a QES:

• Passport or ID card
• Tax number
• Completed application (online or in person)
• A storage device (flash drive, token, or select a cloud-based option)

The process is simple and typically takes 15–30 minutes to complete.

How to verify the authenticity and type of an e-signature

An electronic signature holds legal validity only if its certificate is active and valid. This can be verified through official online services, such as those provided by the Key Certification Center (KCC) or the Diia.Signature platform.

Once you upload the signed document or the certificate file, the system will display:

• the type of signature (SES, AdES, or QES),
• the signer’s identity,
• the date and time of signing,
• and the status of the certificate.

A QES certificate may be considered invalid in the following cases:

• The certificate has expired (typically after 1–2 years).
• It has been revoked — for example, due to a change in the signer’s position or termination of employment.
• The private key has been compromised or lost (e.g., a missing token or lost access to a cloud account).
• The certificate was issued by a non-authorized provider or found to be forged.

To minimize legal and operational risks, large companies implement routine verification of QES certificates in their document workflows — especially in contracts, financial documents, and regulatory reporting.

Are Ukrainian QES recognized in the European Union?

As of 2025, Ukraine is in the process of aligning its electronic trust services with the EU’s eIDAS regulation. Full mutual recognition of Ukrainian qualified electronic signatures (QES) in the EU is expected to take effect by 2027, following the completion of technical and legal integration.

In the meantime, pilot projects are already being implemented that allow partial use of Ukrainian QES in cross-border interactions — for example, in communication with public authorities or document exchange with European partners. New solutions are also emerging, such as Diia.Signature-EU, which comply with eIDAS standards and pave the way for electronic interaction with EU institutions.

Since the mechanism is not yet fully automated, it is currently recommended to:

• either use e-signatures from both jurisdictions for legally binding international agreements,
• or employ cross-border cloud signature services that support eIDAS compatibility.

Cloud-based signature – what it is and why it’s convenient

In recent years, QES has increasingly been issued in cloud format. In this case, your private key is not stored on a physical device (like a flash drive or token), but securely hosted in the cloud by a certified provider. When you sign a document, the system authenticates you — for example, via BankID, password, or SMS code. Once verified, the document is signed automatically in the cloud, and you receive a legally valid signed file.

This is highly convenient: you can sign from any device, without needing to carry a token or install extra software. This model is ideal for companies with decentralized structures or mobile teams.

Why an electronic signature is more than a “digital autograph”

An e-signature is not a standalone feature — it’s a natural step in an end-to-end document workflow. If treated as a separate action, it introduces delays, duplications, and manual friction. For instance, a contract might get stuck in legal review simply because the final signature requires using a separate tool or physical token.

But when the signature is integrated into an electronic document management system (EDMS), the entire process is streamlined: approvals, timestamps, storage, archiving, reminders — all happen automatically.

In other words, an e-signature should live inside the system — as a seamless part of the process, not a “quest” for an accountant, lawyer, or HR manager.

Integrating e-signatures into corporate workflows enables you to:

• maintain a continuous, uninterrupted document flow
• avoid duplicate steps and inefficiencies
• automate contract approvals and signing
• reduce costs related to paperwork — both direct (printing, archiving) and indirect (employee time, delays)

An e-signature isn’t just a “convenient way to sign a contract” — it’s a tool of digital maturity. But it only unlocks its full potential when it’s part of a unified digital infrastructure. That’s why implementing an EDMS is a logical next step for businesses aiming not just for digitization, but for true digital transformation.

Instead of fragmented tools, you get a single controlled workflow — from document creation to archiving.

This is a strategic move toward sustainable digital growth.