By understanding how to make a digital signatureMany companies come to the same question: A1 or A3 digital certificate It's not just the storage format that changes, but also the operational routine, recurring costs, team mobility, and the level of friction in signature processes, tax issuance, and system integration. In practical terms, both have legal validity within the ICP-Brasil framework, but they work better in different scenarios of use, volume, and governance.
The A1 card is usually more suitable for companies that need fluidity, automation, and recurring use in ERP systems, invoice issuance, and internal workflows with greater scale. The A3 card, on the other hand, still appears in operations that value cryptographic media, more controlled use, and lower activation frequency. The correct choice tends to stem less from personal preference and more from objective criteria of productivity, operational risk, renewal, and compliance.
In corporate practice, comparing only the issuance price often leads to incomplete decisions. The real gain appears when the company considers the time spent per operation, hardware dependencies, impact on distributed teams, platform compatibility, and how well the certificate reflects the digital maturity of the business.
Summary
- A1 and A3 are legally valid, but differ in storage, mobility, and how they are used.
- The A1 model typically favors automation, integration with ERP systems, and recurring business routines.
- The A3 can handle one-off transactions, with usage controlled by token, card, or cloud.
- Companies should compare total cost, operational failures, execution time, and scale of use.
- The regulatory landscape has evolved, so periodic review of the selection process has become even more necessary.
Quick facts
- According to Federal policeA1 certificates are valid for one year and A3 certificates for three years in the context presented for business use within the GESP system.
- According to the ICP-Brazil Steering CommitteeA1 certificates remain valid and usable until March 02, 2029.
- According to Resolution CG ICP-Brasil No. 211/2024Types A3 and A4 began to be issued exclusively to individuals, while the electronic seal was defined for legal entities.
How to evaluate A1 or A3 digital certificates in a company's daily routine?
Before looking at suppliers, it's worth mapping out the process. A company that signs contracts in volume, runs integrations with management systems, and needs to reduce bottlenecks usually evaluates the certificate as a piece of operational infrastructure, not as an isolated IT item. This point changes the entire analysis.
When used daily, the certificate ceases to be an accessory and begins to influence productivity, internal SLAs, commercial response, and cost per document processed. In such scenarios, the decision between A1 and A3 should consider frequency, number of users, backup needs, and fault tolerance.
What are A1 and A3 certificates?
Category A certificates are designed for digital signatures and authentication with integrity verification. The A1 model is issued as a digital file, while the A3 is traditionally linked to cryptographic media, such as a token or card, although there are variations in cloud usage depending on the certification authority's policy.
In the business world, this distinction directly impacts operations. A1 tends to be simpler for installation, secure backup, and software integration. A3, because it requires a physical medium in many scenarios, adds a layer of control but can also increase friction in the daily work of teams that depend on speed.
Legal validity and scope of use
From a legal standpoint, the basis lies in ICP-Brasil. This means that the comparison is not between a valid model and an invalid one, but between two formats that may serve distinct business needs. For those dealing with contracts, ancillary obligations, and authentication, this difference in classification needs to be very clear.
In many teams, there's still the misconception that an A1 or A3 corporate tax certificate is only useful for issuing electronic invoices (NF-e). This understanding is limited. In the content we produce about... ICP-BrazilWe explained that the very structure of the certification helps to show that the application is usually broader when the CA's policy does not restrict its use.
Throughout the public guidelines, the ITI It clarifies that digital certificates for legal entities of types A1 and A3 are for broad, general, and unrestricted use, without exclusive limitation for invoices or a single purpose, unless expressly provided for in the policy of the issuing certification authority.
Storage and mobility
This is usually the most visible divider. The A1 file is installed on a compatible machine or environment, which facilitates its use in automated routines and on more than one device within a secure backup policy. The A3 file, in its most well-known form, depends on a token or card connected at the time of use.
To understand this contrast, it's worth noting what the portal gov.br It describes: the A1 card is valid for one year and can be installed on multiple computers with file backup, while the A3 card usually uses a token or card and requires a computer connection each time it is used.
In companies with hybrid teams, distributed operations, or multiple issuance points, this detail is quite important. Those who use certificates at a single station may find physical media more suitable. However, those who need continuity, controlled redundancy, and less dependence on local presence generally find the A1 model more advantageous.
Need for token, card or hardware
Hardware can be seen as an advantage or a limitation, depending on the process. In more specific operations, the token creates a controlled and well-defined usage ritual. In frequent operations, it can become a bottleneck, whether due to driver incompatibility, machine changes, physical loss of the device, or queues between users.
On the concepts page of ITIThe token is described as a secure storage device for the digital certificate with a USB connection. This feature helps explain why the traditional A3 token can be perceived as more rigid to handle and less fluid in highly repetitive business processes.
When legal, financial, and tax departments share the same need for signature or authentication, the existence of a physical medium can create dependence on a specific person, a specific machine, or a specific time. This type of concentration tends to increase operational risk and reduce process flexibility.
Practical comparison between A1 and A3 for businesses
Instead of comparing models solely based on validity, it's worthwhile to cross-reference operational and financial criteria. A company that signs ten documents per month assesses the problem differently than another that issues hundreds of tax documents, integrates systems, and needs to sustain continuous operation without interruption.
| Criterion | A1 | A3 | Reading for the company |
|---|---|---|---|
| Storage | Digital archive | Token, card or equivalent model | The A1 tends to favor automation; the A3 tends to require more operational handling. |
| Shelf life | Minor | Greater in many scenarios. | The A3 may reduce renewal frequency, but this does not solve usage bottlenecks. |
| Internal mobility | High, with security policy | Average or low, depending on the media. | The A1 model typically works best in distributed teams and systems. |
| Integration with ERP | Simpler | It may require additional steps. | For automated processes, the A1 generally offers less friction. |
| Risk of unavailability | Related to backup and file management. | Related to the loss, damage, or absence of media. | Both require governance, but the type of risk differs significantly. |
If the central criterion is integration with management software, the A1 certification usually comes out on top. Therefore, it becomes clear how automation depends on fewer technical barriers between the certification and the environment where the operation actually takes place.
Operating time and productivity
A useful KPI here is the average time to complete an action that depends on the certificate. This could be signing a batch, authenticating access, issuing tax documents, or executing a step in the financial closing process. The more repetitive the task, the more relevant it becomes to eliminate manual steps and physical dependencies.
In a scenario with recurring use, the A1 tends to reduce the time per operation because it eliminates the need to connect media, validate the physical presence of the device, and work around basic hardware unavailability. This usually translates into increased productivity per employee and less impact on internal deadlines.
Operational failures and continuity
Another important KPI is the incidence of failures. This includes token loss, forgotten passwords, reader incompatibility, computer replacement, inability to use the device remotely, and downtime due to device absence. The cost of these failures rarely appears in the certificate price, but it weighs heavily on the total cost of ownership.
Companies that are already discussing processes management e process optimization They tend to notice this effect more quickly. A certificate can be cheap to acquire but expensive to operate, especially when it becomes a bottleneck between departments, approvals, or customer service windows.
Renovation cost and total cost
The A3 certification may seem advantageous due to its longer validity period in many business contexts, reducing the need for frequent renewals. However, this point alone doesn't add up. The total cost involves team hours, support, interruptions, device requirements, and potential downtime caused by a certificate that doesn't align with the actual workflow.
The A1 certificate typically requires more frequent renewals, but this shorter interval is offset when operations depend on speed, integration, and recurring use. For those seeking structural cost reductions, the calculation needs to consider the cost per completed operation, not just the unit cost of the certificate.
Example of a company with recurring usage.
Consider a software house with a daily volume of contracts, recurring document issuance, and teams integrated with CRM, ERP, and finance. In this case, the company tends to benefit more from a certification that supports automation and reduces manual intervention. The A1 certification makes more sense because it aligns better with scalability and repetition.
In this same context, topics such as electronic signature for companies e Digital Signature ROI They help visualize the real gains: shorter processing times, fewer execution errors, and a better customer experience during the formalization stages.
Example of a company with occasional use.
Now imagine a smaller company, with low usage frequency, few responsible parties, and a preference for a more centralized process. If the certificate is activated at specific times and under the control of a single point, the A3 can still work well, provided that the media dependency does not generate significant delays.
In this case, the company more readily accepts the ritualization of usage. The switch may be reasonable when the volume is low, the need for automation is limited, and the process does not depend on multiple people or multiple systems working simultaneously.
Check out these related articles as well:
- Signing with a digital certificate helps to understand in which corporate workflows the certificate is most effectively used.
- Cloud-based digital certificates: how they work shows where mobility and governance can coexist more seamlessly.
- How to sign a document with a digital certificate details the practical application of the certificate in signature routines.
There is still a regulatory point that needs to be on the manager's radar. The modernization of ICP-Brasil created the electronic seal for legal entities and defined a regulatory transition. This does not invalidate the current debate between A1 and A3 for companies immediately, but it shows that decisions made today need to be reviewed periodically.
When dealing with digital compliance e digital signature complianceIt is worth considering not only the most suitable current model, but also the company's ability to adapt its flows, suppliers, and integrations to regulatory and technological changes in the coming years.
Which choice tends to work best in each business scenario?
For most companies seeking agility, ERP integration, less hardware dependence, and increased productivity in recurring tasks, the A1 tends to be the most coherent option today. For one-off, centralized operations with less need for automation, the A3 can still consistently meet the needs.
The main point is that A1 or A3 digital certificate It should be reviewed in light of the actual process, scale, volume of subscriptions and issuances, failure indicators, and the company's compliance design. When the decision is guided by operations and not just by custom, it becomes easier to reduce costs, preserve security, and increase efficiency.
In this context, your company can evaluate the ZapSign's digital certificate solution as part of this analysis.
Frequently Asked Questions (FAQ)
What is the main difference between an A1 and an A3 certificate?
The most well-known difference lies in storage. A1 functions as a digital file installed in a compatible environment, while A3 typically relies on a token, card, or other controlled media. This distinction affects mobility, system integration, speed of use, and the operational risk involved in frequent business routines.
Is the A1 certificate less secure than the A3 certificate?
It's impossible to draw a general conclusion. Both fall under the logic of digital certification and require good governance practices. What changes is the type of risk. In A1, the focus is on backup, access control, and file management. In A3, greater care involves the possession, preservation, and availability of the cryptographic media.
Which model typically works best for integration with ERP systems?
In general, the A1 form tends to be more compatible with ERP integrations and business automation systems because it operates as a digital file and reduces hardware friction in the workflow. This often favors recurring issuance, system authentication, and high-volume processes. However, compatibility depends on the software used and the vendor's policy.
Can companies still use A1 and A3 certificates?
Yes. The regulatory framework has been updated, but A1 certificates remain valid until March 02, 2029, according to the ICP-Brasil Management Committee. Therefore, the discussion remains relevant for ongoing operations. What has changed is the regulatory direction, which requires more attention to the periodic review of processes and the certification strategy.
How to choose between A1 and A3 without making a mistake?
The best approach is to compare usage frequency, number of users, system integration, mobility needs, renewal costs, failure rates, and impact on productivity. When a company measures time per operation and hardware dependency, the choice ceases to be abstract and begins to reflect what actually happens in daily operations.
Getúlio Santos is the CEO of ZapSign, a lawyer, technology enthusiast, and entrepreneur.
