AI-powered medical certificates: from paper to a digital HR workflow

In outsourcing companies, a medical certificate often takes a long trip: it leaves the doctor's office in the employee's bag, passes through the site supervisor, sometimes becomes a blurry WhatsApp photo and only reaches HR days later — if it arrives at all. Artificial intelligence shortens that path: the employee photographs the document, the system reads the data and HR receives everything organized, ready to check and approve. This guide is based on Brazilian legislation and labor practice, and explains how the workflow works, which checks cannot be skipped and what labor law, the rules of the Federal Council of Medicine (CFM) and the LGPD, Brazil's data protection law, require.

The problem with paper certificates in distributed teams

When operations are spread across dozens of sites, each paper certificate becomes a small logistics project. The most common problems:

• Lost documents: the certificate goes missing between the site, the supervisor and the office.
• Illegibility: hard-to-read handwriting, smudged stamps or shaky photos hide the doctor's name, their CRM (registration number with the Regional Medical Council) or the number of days off.
• Delays: the certificate arrives after payroll closes, the absence is deducted and, weeks later, it becomes a reversal and friction with the employee.
• Manual typing: someone retypes dates, the doctor's name and CRM — and every keystroke is a chance for error.
• No traceability: nobody knows for sure who received it, when and what was decided.
• Exposed health data: certificates circulating in messaging groups or left on a supervisor's desk.

Brazilian law does not set a specific deadline for handing in a certificate, as the TST (Superior Labor Court) has pointed out in guidance material. That rule must therefore be clear in the internal policy, in line with anything the applicable collective agreement may establish.

What Brazilian law says about certificates and justified absences

Proven illness is a justified reason

Lei nº 605/1949, which governs paid weekly rest, lists among justified absences "the employee's illness, duly proven" (art. 6, § 1, "f"). Paragraph 2 sets an order of preference for the doctors who may issue the certificate, starting with the social security institution's doctor and reaching a doctor of the employee's choice only when the others are not available locally. Súmula 15 do TST (a consolidated precedent of the Superior Labor Court) reinforces this order, and Súmula 282 gives the company's medical service, in-house or contracted, the role of excusing the first 15 days of absence. Before rejecting a certificate based on this order, check with your legal team and the collective agreement.

Other legal absences also require proof

Article 473 of the CLT (Brazil's Consolidated Labor Laws) lists absences that do not reduce pay, and several require proof: voluntary blood donation (one day every 12 months), accompanying a wife or partner to up to six prenatal appointments or exams, taking a child aged up to 6 to a medical appointment (one day per year) and preventive cancer screenings (up to three days every 12 months). A good digital workflow handles these documents just like medical certificates.

The first 15 days and the 60-day rule

For sick leave, the employer pays full salary for the first 15 consecutive days (Lei nº 8.213/1991, art. 60, § 3); after that, the case moves to the INSS, Brazil's social security institute. In eSocial, the government's digital system for reporting labor and social security obligations, leave for illness not related to work (event S-2230) must be reported, among other cases, when it lasts more than 15 days or when absences for the same illness within 60 days add up to more than 15 days — with a deadline on the day the 16th day of absence is reached. A late certificate can therefore also jeopardize an eSocial deadline.

What a certificate must contain

CFM Resolution nº 2.381/2024, which regulates the issuance of medical documents, requires every document to include at least: the doctor's name and CRM/state; RQE (specialist registration), when applicable; the patient's name and CPF (taxpayer ID), when available; date of issue; signature (qualified, if electronic, or with stamp or CRM number, if handwritten); professional contact details and address. A sick-leave certificate must also state the number of days off.

The same resolution distinguishes documents that HR teams often confuse:

Document	Issued by	What it proves	Practical effect
Sick-leave certificate (atestado de afastamento)	Doctor	Care provided and days off needed for recovery	Justifies the absence for the stated period
Companion certificate (atestado de acompanhamento)	Doctor	Presence of the person who accompanied the patient, with date and number of days	May prove absences such as those in art. 473 of the CLT
Attendance statement (declaração de comparecimento)	Administrative staff of the healthcare facility	Attendance at the appointment, with no recommendation of leave	May justify the absence, provided the employer agrees

ICD codes only with the patient's authorization

The diagnosis, coded or not (the ICD code, called CID in Brazil), may only appear on the certificate for just cause, by legal duty or at the request of the patient or their legal representative — and, in that last case, the consent must be stated on the document (CFM Resolution nº 2.381/2024, art. 5, §§ 3 and 4). The TST's Collective Disputes Section has also upheld the nullity of a collective agreement clause requiring the ICD code to validate certificates, because it violated workers' intimacy and privacy (RO-213-66.2017.5.08.0000). In practice, a digital workflow should never make the ICD code mandatory and, when it does appear, access to it must be restricted.

How AI reads a medical certificate

Reading tools combine optical character recognition (OCR) with AI models that understand the document's structure: beyond "reading letters", the system must know what is a date, a CRM or the number of days off. The typical workflow:

1. Capture: the employee photographs the certificate in the app, or uploads the PDF if the document is digital.
2. Extraction: the AI identifies the patient's name, date of issue, start of leave, days granted, the doctor's name, CRM/state and the document type.
3. Employee review: the fields appear pre-filled; the employee checks them, corrects what is needed and submits, with the original image attached.
4. HR review: HR validates, approves or rejects, and the absence is linked to the employee's timesheet.

In TIRVU+, for instance, the employee just reviews the data the AI filled in from the photo and submits it; HR approves it in the web panel, with no retyping.

An important principle: AI suggests, a person decides. This is consistent with the LGPD, which gives data subjects the right to request a review of decisions made solely on the basis of automated processing (art. 20).

Validation best practices

Automatic reading solves the typing; validation remains HR's job. The points that deserve the most attention:

• Active CRM: the CFM's public doctor search lets you check the doctor's name, CRM and state.
• Consistent dates: issue date, start of leave and days granted must match each other, the schedule and the clock-in records. A certificate for a day off justifies nothing.
• Duplicates: the same document submitted twice, or two certificates for the same period, should trigger an alert.
• Digital documents: for electronic certificates, check the signature on the official validator run by ITI, Brazil's National Institute of Information Technology (validar.iti.gov.br).
• Document type: an attendance statement is not the same as a sick-leave certificate.
• Cumulative leave: track the 60-day windows and involve the company's medical service in recurring cases.

What about the Atesta CFM platform? Established by CFM Resolution nº 2.382/2024 as the official system for issuing and managing certificates, it has been suspended by a court decision, according to the CFM itself. For now, verification depends on the document's data and the checks above.

Suspected fraud calls for extra care. Brazil's Penal Code makes it a crime for a doctor to issue a false certificate (art. 302) and to use a forged document (art. 304), and the CLT provides for dismissal for just cause due to dishonesty (art. 482, "a"). Given the stakes, any suspicion should be investigated in a documented way and with legal support: AI points out inconsistencies, not culprits.

LGPD: a medical certificate is sensitive data

Health information is sensitive personal data (LGPD, art. 5, II), and it may only be processed in the cases listed in art. 11 — in the employment context, the usual legal bases are compliance with a legal or regulatory obligation and the regular exercise of rights (art. 11, II, "a" and "d"). In day-to-day work, this means:

• Necessity: only those who need to see the certificate see it. The site supervisor — and the client, in the client portal — needs to know the absence is justified, not what the document says.
• Security: role-based access control, logs of who viewed each document and protected storage (art. 46).
• Official channel: no WhatsApp groups or printed copies going around.
• Defined retention: agree with your legal team how long to keep documents, considering the statute of limitations for labor claims (Federal Constitution, art. 7, XXIX).

Separate environments for employees, managers and clients, like the ones in TIRVU+, help enforce this principle without relying on each user's goodwill.

Paper vs. AI-powered digital workflow

Step	Paper certificate	Digital workflow with AI
Submission	In person, requires travel	Photo in the app, same day
Reading	Manual, prone to illegibility	Automatic extraction, reviewed by the employee
Data entry	Retyped by HR	Fields pre-filled and linked to the timesheet
eSocial deadlines	At risk with late documents	Cumulative leave visible in real time
Traceability	Almost none	History of submission, review and decision
Privacy	Document passes from hand to hand	Role-based restricted access

Checklist to roll out digital medical certificates

• Certificate policy published, with submission deadline, accepted channels and document types
• Employees trained to photograph the document and review the data
• Reviewers defined, with backups
• Validation criteria documented: CRM, dates, duplicates and document type
• Alerts set up for cumulative leave within 60 days
• Access profiles reviewed under the necessity principle
• Integration with schedules and timesheets tested
• Retention period defined with the legal team

Frequently asked questions

How long does an employee have to hand in a medical certificate?

Brazilian law does not set a specific deadline, as the TST (Superior Labor Court) has pointed out in guidance material. The deadline should therefore be spelled out in the company's internal policy, in line with anything the applicable collective agreement may establish.

Can an employer require the ICD code (CID) on a medical certificate?

In practice, the code should not be mandatory. CFM Resolution nº 2.381/2024 only allows the diagnosis to appear on the certificate for just cause, by legal duty or at the request of the patient or their legal representative, and the TST's Collective Disputes Section has upheld the nullity of a collective agreement clause that required the ICD code to validate certificates, because it violated workers' intimacy and privacy. When the code does appear, access to it must be restricted.

Does AI replace HR in reviewing medical certificates?

No. AI reads the photo and pre-fills the fields, but validation remains HR's job: HR should check the CRM, dates, duplicates and document type before approving or rejecting the certificate. AI suggests and a person decides, in line with the LGPD, which gives data subjects the right to request a review of decisions made solely on the basis of automated processing (art. 20).

Conclusion

The medical certificate does not have to be HR's most fragile document. With AI-powered reading, employees submit in minutes, HR stops typing and starts validating, and the company gains control over deadlines and better protection for health data. The balance is clear: automation for capture, human judgment for decisions, and respect for CFM and LGPD rules. To align this workflow with time tracking, also read our complete guide to Portaria 671, Brazil's electronic time-tracking regulation.

Want to see how TIRVU+ turns a photo of a medical certificate into a record ready for approval, integrated with time tracking and schedules? Talk to our team and book a demo.

Sources

• TST: the difference between a medical certificate and an attendance certificate (2016)
• Planalto: Lei nº 605/1949, on paid weekly rest
• Planalto: Lei nº 8.213/1991, on social security benefit plans
• CFM: Resolution nº 2.381/2024, on issuing medical documents
• TST: clause requiring ICD codes on certificates held void (2019)
• ITI: digital signature validator

This content is for informational purposes only and does not replace specialized legal advice.