What are the 10 types of digital signature errors and how to avoid them?

Um error in digital signature This can occur when the document has been altered or corrupted, the certificate has problems, the signature is not recognized, or technical information is missing to complete the validation. The first step is to send the original file to ITI's VALIDAR system and consult the compliance report, which shows whether the signature was approved, rejected, or considered indeterminate.

Summary

• What are the main causes of errors in digital signatures?
• How to interpret the results of the ITI's VALIDAR test.
• What to do when the signature appears as indeterminate.
• How to identify changes or corruption in a document.
• What precautions should be taken with digital certificates?
• How to avoid printing, initialing, and sharing errors.

Quick facts

1. Three possible outcomes: The VALIDATE tool classifies the signature as approved, indeterminate, or rejected. An indeterminate result means that there is insufficient information to confirm or reject its compliance.
2. Certificate expired: The current expiration date of the certificate does not automatically invalidate documents signed during its validity period, considering the time source used for signing.
3. Changes to the PDF: The absence of DocMDP or FieldMDP features may prevent VALIDAR from determining whether the file has been modified and generate the result "indeterminate signature".

What can cause errors in digital signatures?

In Brazil, the validity of digital signatures is supported by Provisional Measure No. 2.200-2/2001, which establishes the Brazilian Public Key Infrastructure (ICP-Brasil). This structure guarantees the authenticity, integrity and legal validity of digitally signed documents.

A digital signature is different from a common electronic signature, as it uses digital certificates linked to the signatory's CPF or CNPJ, which ensures a higher level of protection against fraud.

Despite the regulation and popularization of the use of digital tools, many mistakes are still made when signing a document. These errors can nullify the legal effect of the file or generate uncertainty regarding its authenticity. Below, we present the main types of mistakes made in this process and how to avoid them.

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10 mistakes in digital signatures and how to fix them.

The adoption of digital signatures in Brazil represents an important step forward in streamlining processes and securing electronic transactions. Below, learn about the main mistakes made when using this technology and see how to avoid them in a practical way.

1. Use of rubrics in digital documents

Many people still have the habit of applying rubrics to pages of printed documents as a way of validating the content. This custom has been transferred to the digital environment by some users who insert gallery of your signatures in PDF files or electronic documents. This practice has no legal validity and does not represent a recognized digital signature.

How to avoid: Instead of trying to reproduce habits from the physical world, it is necessary to use reliable digital signature platforms, which link the signatory to a digital certificate and guarantee cryptographic verification of the document.

2. Unnecessary repetition of signatures

Another common mistake occurs when the same signatory makes multiple signatures on the same document, believing that it is necessary to validate each section or page. This practice, in addition to being redundant, can raise doubts about the integrity of the content, especially when there are subsequent edits between one signature and another.

How to avoid: signing once at the end of the document, using a tool that records the integrity of the content, is enough to guarantee its validity. technology used by specialized platforms ensures that any subsequent changes invalidate the original signature.

3. Printing digitally signed documents

There are cases where, after digitally signing a document, it is printed for physical archiving or sending to third parties. This procedure both invalidates the digital signature (which depends on encryption for verification) and also removes the document's traceability and certification of authenticity.

How to avoid: Digitally signed documents should be kept and shared only in digital format. Ideally, the file should be stored in a secure environment and, when necessary, validated by specific tools that confirm the integrity of the signature.

4. Creating duplicates to collect new signatures

Some professionals choose to generate a new copy of an already signed document to include additional signatures. The problem is that, when creating this new version, the previous signature loses validity or is no longer linked to the original content, opening the door to fraud.

How to avoid: The correct order is to enter all signatories into the same digital signature process. Good platforms allow sequential or simultaneous sending to multiple parties, ensuring that each signature is securely recorded in the same original file.

5. Signature out of defined sequence

In certain workflows, it is important that signatures follow a logical sequence, especially in approval processes. When this flow is not followed, the document may be finalized before all parties involved have reviewed it, which compromises reliability.

How to avoid: Use tools with signature order control. This way, each party can only sign after prior validation, maintaining process consistency.

6. Use of platforms that do not comply with standards

Not all platforms guarantee compliance with Brazilian legislation or international security standards. Some solutions only simulate a visual signature, without applying the necessary layers of protection to ensure legal validity.

How to avoid: Choose platforms that are recognized and aligned with ICP-Brasil, which guarantee the integrity and authorship of the document. Check whether the tool has automatic signature validation and protection against changes.

7. Manual insertion of signature images

Instead of using legitimate digital signatures, some people insert images of their own handwritten signature into the digital document – ​​which may seem like a quick way to get things done, but it is not a authentication valid.

How to avoid: Always choose to sign using secure digital methods, with identity verification. Inserting images is easily manipulated and is not legally recognized as a digital signature.

8. Misuse of the digital certificate

There are situations in which the digital certificate is shared between employees or used on public machines – which compromises the security of the holder and can lead to the cancellation of the signatures made.

How to avoid: The digital certificate is personal and non-transferable. It must be protected by a strong password and used only by the authorized holder, on trusted devices and with two-step authentication, if possible.

9. Lack of document validation after signature

Digitally signing the file without validating it is another common mistake. Without the final check, the document may contain errors or have been changed before signing, without the signatory's knowledge.

How to avoid: After signing, use a validation tool to ensure that the content is complete and that the signature is recognized as valid. The National Institute of Information Technology (ITI) offers a free public validator for this purpose.

10. Lack of record of stock history

The signing process is not always recorded transparently. The lack of a history makes it difficult to prove who signed, when and in what order, compromising traceability and confidence in the process.

How to avoid: use platforms that record the entire activity history, including date, time, IP and signature order – which helps to prove the authenticity of the process in the event of legal challenges.

Error or result	Possible cause	How to solve
Document without signature or corrupted signature.	Corrupted file, incorrect download format, or improper sharing.	Request a new original file from the issuer.
Indefinite signature	Lack of technical information, expired certificate, or missing DocMDP/FieldMDP.	Open the compliance report and consult the supplier.
Signature rejected	A compliance failure was identified during validation.	Review the report messages and request a new signature.
Unknown signature	Unrecognized chain or anchor of trust	Consult the issuer or the certification authority.
Document modified	Modification made after signing.	Recover the original file or perform a new process.
Error 500 or API failure	Temporary service instability	Refresh the page and try again later.

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How to avoid errors in digital signatures?

Avoiding the aforementioned errors involves consciously choosing the tool used and clearly understanding how the digital signature process works.

For a document to be legally valid, it must maintain its integrity from start to finish, be authenticated by a digital certificate issued by a trusted authority, and not be altered after signing. Every technical detail matters, from the signatory's identification method to the security structure applied to the signature.

It is also essential that the user is correctly identified, that access is controlled and that the platform used accurately records all steps taken — such as times, IP addresses and order of signatures. These records offer an additional layer of protection in the event of an audit or legal challenge.

The most effective way to prevent any type of error in digital signatures is to invest in a solution that fully meets the requirements of the legislation, applies robust data protection measures and, at the same time, is easy to operate on a daily basis. This significantly reduces the margin for error and the signature process becomes more reliable and secure for all parties involved.

Having said all this, we can see how digital signatures represent a significant advance in the digitalization of processes, but their use requires attention to details that guarantee the legal validity and security of information. Making a mistake in digital signatures can compromise important contracts, open loopholes for fraud and invalidate essential documents.

Avoiding errors such as the use of signatures, insertion of images, printing of signed files and inappropriate use of certificates is the responsibility of companies and professionals.

Platforms like ZapSign offer legal security and a simplified signing experience, with integration into management systems, automated sending and validation in compliance with ICP-Brasil.

Adopting good practices and using reliable platforms are the safest ways to enjoy all the benefits of digital signatures. If you are looking for a solution that facilitates this process safely, transparently and economically, Discover ZapSign and transform the way your company signs documents.