Learn how to make a contract with a digital signature in 10 steps

Contract with digital signature It is an electronic contract signed using a cryptographic method that binds the signatory to the document and allows verification of its integrity. In Brazil, contracts can also be signed using other types of electronic signatures, and validity does not automatically depend on an ICP-Brasil certificate: it is necessary to consider the method used, the evidence produced, and any specific legal requirements.

In practice, companies can create the contract, register the parties, configure authentications, collect signatures, and maintain the file and its records in a digital environment. This can simplify the process. records management and reduce physical steps, provided that the workflow is compatible with the risk and the nature of the business.

In this article, we explain the difference between digital and electronic signatures, how encryption works, what legal precautions to take, and how to create a contract with a digital signature on ZapSign.

Summary

• Contracts with digital signatures use cryptography and digital certificates to enable authentication and integrity verification.
• Not all electronic contracts necessarily require an ICP-Brasil certificate to produce legal effects.
• The choice of signing method should take into account the type of contract, the risk involved, and the applicable legal formalities.
• A good workflow includes contract review, identification of the parties, authentication, signing, and preservation of evidence.
• ZapSign allows you to configure digital certificates and other authentication methods according to the chosen process.

Quick facts

• Other methods are permitted: a Provisional Measure No. 2.200-2/2001 It allows for the verification of authorship and integrity through means other than ICP-Brasil when admitted by the parties or accepted by the recipient of the document.
• Three options: a Law No. 14.063 / 2020 It classifies electronic signatures as simple, advanced, and qualified; the latter uses a digital certificate in accordance with ICP-Brasil standards.
• Recent understanding: on 2026, the The Superior Court of Justice (STJ) recognized the validity of an electronic transaction. The signature was signed on a platform not certified by ICP-Brasil, and the author stated that the absence of accreditation, in itself, does not invalidate the signature.

What is a contract with a digital signature and what is an electronic signature?

Contract with digital signature It is an electronic document whose signature is produced using cryptographic technology. A digital signature is a type of... electronic signatureIt uses a digital certificate, a private key controlled by the holder, and a public key that allows verification of the signature.

In simplified terms, the system calculates a cryptographic summary of the document. The private key is used in the signature creation process, and the public key linked to the certificate allows verification that the signature corresponds to the holder and that the content has not undergone changes incompatible with the validation.

"Electronic signature," on the other hand, is a broader concept. It can involve methods such as confirmation via email, SMS, WhatsApp, biometrics, account authentication, or other mechanisms capable of recording the expression of will and generating evidence of authorship and integrity.

Element	Electronic signature	Digital signature
Definition	A broad form of expressing one's will through electronic means.	A type of electronic signature based on cryptography.
Mechanism	You can use different authentications and evidence.	Uses digital certificate and cryptographic key pair
Verification	It depends on the method and the evidence produced.	It allows you to verify the signature with the public key linked to the certificate.
ICP-Brazil	It is not mandatory in all modalities.	When executed with an ICP-Brasil certificate, it constitutes a qualified electronic signature.

When we founded ZapSign, we had two principles that continue to guide my perspective on this issue: the signature needed to be legally valid and, at the same time, simple to use. Security shouldn't mean unnecessary additional bureaucracy; the method needs to be proportionate to the risk and formality that the contract actually requires.

How do I draft an electronic contract before signing it?

Before signing, the contract must be complete and accurately reflect the agreement between the parties. Technology cannot correct poorly drafted clauses, incorrect data, or a version sent in error.

1. Choosing the platform or software

Choose a platform or with Compatible with the workflow your company needs. Consider document volume, users, authentication methods, audit trail, integrations, support, and the possibility of using a digital certificate when necessary.

2. Contract template

Use a template appropriate to the contractual relationship or draft the document from scratch. The template should serve as a starting point, not replace an analysis of the specific details of each negotiation.

3. Insertion of clauses and information

Include identification of the parties, subject matter, obligations, amounts, payment terms, deadlines, grounds for termination, and other relevant provisions. Depending on the transaction, other legal or regulatory clauses may be required.

4. Review and editing

Review the content, names, documents, values, dates, and attachments before signing. When there is greater complexity or legal risk, review by a qualified professional may be appropriate.

5. Choosing a subscription method

Define whether the contract will use simple, advanced, or qualified signatures. As a general rule, not every party needs to use an ICP-Brasil certificate in every private contract. The chosen method must comply with applicable legislation, be accepted by the parties, and meet the required level of evidence.

6. Storage and management

After completion, preserve the final document and records linked to the process. Access control, backups, retention policies, and audit trails help keep the archive available and verifiable when needed.

In a contract with digital signatures, how is the identification of the parties using digital certificates carried out?

When a contract uses a qualified digital signature, the digital certificate links an identity to the respective pair of cryptographic keys. This allows for technical verification of the signature and the certificate used in the process.

1. Valid digital certificates

Signatories who will use a qualified signature must possess a valid digital certificate issued under the ICP-Brasil framework and compatible with the chosen workflow.

2. Verification of certificates

It is possible to verify information such as certificate validity, chain of trust, and signature status using compatible tools, including official validators when applicable.

3. Electronic submission of the contract

Once the document is prepared, the platform generates the signature workflow and provides access to signatories via a link or through the configured channels.

4. Notification of parties

Participants receive the necessary instructions to open, review, and sign the contract. Before finalizing, each person must verify that they have received the correct document and agree with its contents.

5. Digital signature of the contract

The signer uses their certificate and corresponding authentication mechanisms to complete the signature. The private key must remain under the control of the holder, as it is a sensitive component of the digital identity.

6. Confirmation and preservation

After everyone has signed, preserve the final version of the contract and the data that allows verification of the process. Avoid recreating the file by printing or editing it later if this eliminates or compromises the existing signatures.

Does an electronic contract require an ICP-Brasil certificate?

Not in all cases. Provisional Measure No. 2.200-2/2001 establishes a presumption regarding the statements contained in electronic documents produced with ICP-Brasil certification, but its article 10, § 2, also admits other means of proving authorship and integrity when accepted by the parties or the recipient.

Law No. 14.063/2020 also makes it clear that there are three levels of electronic signature. The qualified signature uses an ICP-Brasil certificate, while the advanced signature may use a certificate not issued by ICP-Brasil or another means that meets the legal requirements of authorship, control, and integrity.

There is also an important update for contracts that can serve as an extrajudicial enforceable instrument. A Law No. 14.620 / 2023 The Superior Court of Justice (STJ) added paragraph 4 to article 784 of the Code of Civil Procedure. In a decision published in May 2026, the STJ highlighted that this provision now expressly allows electronic signatures in the formation of electronic enforceable instruments, dispensing with witnesses when integrity is verified by a signature provider.

I wrote about this legal change back in 2023 because it addressed a recurring question for those who digitize contracts: to what extent do we need to reproduce the formalities created for paper in the electronic environment? The legal answer continues to depend on the case, but legislation is increasingly recognizing the specific characteristics of the digital medium.

In March 2026, the Third Panel of the Superior Court of Justice (STJ) also upheld the validity of a loan agreement made on a platform not certified by ICP-Brasil. The court highlighted that the lack of accreditation, in itself, does not invalidate the signature, especially when there is active participation of the contracting party and other evidence of authentication.

The procedure for a contract with digital signature

Once prepared, the contract is made available to the parties. The process may involve email, a secure link, WhatsApp, or other channels, depending on the resources and settings chosen.

Authentication varies depending on the method. A qualified signature requires an ICP-Brasil certificate; an advanced or simple electronic signature may use other mechanisms, such as tokens, biometrics, documents, registration data, or combinations of evidence.

After authentication and expression of intent, the platform registers the signature and corresponding events. In corporate workflows, it is also important to define the order of signatories, deadlines, reminders, and access permissions.

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The importance of securely archiving contracts with digital signatures.

Even after signing, contracts still require careful handling. Preserve the completed electronic version, maintain adequate backups, and implement access controls to reduce the risk of loss, unauthorized alteration, or exposure of information.

It is also advisable to keep evidence associated with the process, such as authentication records, dates, times, events, and audit trails provided by the solution used. These elements help to reconstruct what happened if the document is questioned later.

This point about evidence is particularly important to me. In recent ZapSign projects, including the use of Open Gateway to strengthen identity validation, the concern was to add more security and governance without creating friction for the signer. In digital contracts, experience and the ability to prove something need to go hand in hand.

Contract with digital signature: legal validity and requirements

In Brazil, electronic contracts can produce legal effects, but the analysis should not start from the idea that any method is suitable for any act. It is necessary to consider the capacity and expression of will of the parties, the content of the transaction, the integrity of the document, the method of identification, and any specific formalities.

A qualified signature offers the highest level of reliability within the classification of Law No. 14.063/2020. Even so, Brazilian legislation does not make ICP-Brasil a universal requirement for all electronic private contracts.

In regulated situations, real estate transactions, specific financial operations, dealings with public bodies, or other businesses subject to their own rules, additional requirements may apply. In these cases, confirm the applicable legislation and procedures before deciding on the signature method.

Main benefits of a digitally signed contract

Digitization can reduce printing, transportation, and administrative time, as well as facilitate document organization and allow parties to sign remotely.

To the companiesThe main benefit tends to appear when the subscription integrates with the others. commercial processesContract generation, approval, collection of outstanding payments, storage, and consultation no longer depend on isolated and manual tasks.

This does not mean that digital signatures "guarantee" savings or eliminate risks. The result depends on the volume of documents, the previous structure, the authentication methods chosen, and how the new workflow is implemented.

⚠️ Also check out these related articles 👇

➡️ Learn how to sign with a digital certificate
➡️ Understand what a digital signature verifier is for
➡️ What is a digital contract and how to adopt one for your company

How to create a contract with a digital signature: step by step (10 steps)

The tutorial below shows how to configure a contract workflow with a digital certificate in ZapSign. The original images have been preserved for their educational value, although some interface elements may have changed since the 2024 screenshots.

Step 1: Log in to the system

Visit our website Log in to your account to open the main dashboard.

Step 2: Generate a new document.

Use the option available on the dashboard to create a new document and start the process.

Step 3: Upload the contract.

Select the document to be signed. PDF This is an appropriate format for preserving the layout. Before proceeding, please verify that this is the final version of the contract.

Step 4: Configure the digital certificate.

Register the signatories and open the authentication settings. When the workflow requires a qualified signature, select "Digital Certificate" from the available methods and confirm that each person has a compatible certificate.

Step 5: Add your own signature, if needed.

If you also need to sign, include your name among the signatories and proceed to the next setup.

Step 6: Position signatures and endorsements.

Define the points where signatures, endorsements, or other fields should appear. Avoid overlapping clauses, values, dates, or relevant information, and review the document before saving.

Step 7: Generate and send the subscription links.

Share the links through the available channels in your workflow. The platform may offer manual or automatic sending, depending on your plan and configuration.

Step 8: Organize the signatories

If there is a mandatory sequence, configure the order of signatures. This way, participants can be notified as previous steps are completed.

Step 9: Finalize the procedure.

Review recipients, message, reminders, and other options. After sending, track the progress through the dashboard and identify any pending issues.

Step 10: The signatories finalize the contract.

The signatories open the document, review the terms, and perform the configured authentication. If the method is a digital certificate, the signature is completed with the corresponding certificate. If the workflow uses another type of electronic signature, the evidence will be that specified in that configuration.

The important point is not to confuse the visual design of the signature with the technical proof of the process. What sustains an electronic contract is the combination of the document, the expression of will, the method of identification, the records, and the integrity of the evidence.

If you are not yet familiar with ZapSign's solution, click here right now to speak to one of ZapSign's consultants and to learn about the resources available for electronic contracts and signatures.

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