Accountants & payroll firms

Electronic signature for accountants and payroll firms

Engagement letters, certificates, approval minutes, pay slips, social declarations, management mandates: digitalize all documents signed by your firm and clients with eIDAS proof level. Compliant with Order No. 45-2138, the OEC Code of Ethics, the Commercial Code, the Labor Code (art. L3243-2), and the eIDAS regulation.

Use cases in accounting and payroll practice

All contractual documents of an accounting and payroll firm can be electronically signed, from the engagement letter to the individual social declaration.

Engagement letter

Mandatory under article 151 of the Code of Ethics, the engagement letter must be signed by the client BEFORE the service begins. Remote signature in 2 minutes, qualified timestamp proving prior acceptance of terms and fees.

Accountant's certificate

Certificates for banks (revenue, debt capacity), social bodies (URSSAF), landlords or authorities. AES signature + audit trail = proof of authenticity enforceable.

Minutes of approval of annual accounts

Minutes of ordinary general meetings (article L232-1 of the Commercial Code), with sequential or parallel signature of partners. Automatic maintenance of dematerialized PV register.

Dematerialized pay stub

Compliant with article L3243-2 of the Labor Code (from the 2015 Macron law) and decree no. 2016-1762. Made available in a compliant digital safe, presumed consent of the employee — express refusal possible at any time.

Social and tax management mandate

Mandates by which the client entrusts the firm with the management of social (DSN) and tax declarations (VAT, income tax, business property tax). Advanced signature to identify the principal and trace the precise scope of the mandate.

Service agreements and client commitments

Confidentiality commitments, agreements for specific services outside the engagement letter, outsourcing agreements between firms: the entire contractual scope of the firm is covered.

Why Certyneo for an accounting firm

Six guarantees specifically tailored to the ethical and evidential requirements of the accounting profession.

Strong customer identification

OTP verification SMS + email of the signatory, qualified time stamping, SHA-256 signature of the document.

Audit trail opposable

Each envelope produces a signature certificate: OTP identity, IP, qualified time stamp, SHA-256 hash, which is incorporated into the signed PDF.

Professional secrecy respected

TLS 1.3 encryption in transit, AES-256 at rest, strict data isolation per cabinet. 100% EU hosting (Germany), no outsourcing outside the EU. Standard DPA included, in accordance with the professional secrecy of Article 8 of Order 45-2138.

Archiving in accordance with accounting deadlines

Archiving 10 years including probative value (Article L123-22 of the Commercial Code period for keeping books).

Conforme eIDAS — niveau avancé (AES)

Signature avancée conforme au règlement (UE) n°910/2014. Pour les actes exigeant le niveau qualifié (QES — actes authentiques), notre roadmap intègre un prestataire QTSP partenaire.

Integration with business software

Public REST API, event webhooks, and ongoing integrations with the major accounting production software (CEGID, ACD, RCA, ISACOMPTA, QuadraCompta). Compatible with your existing stack.

Probative value for an accounting firm

The probative value of an electronic signature in an accounting firm depends on two fronts: demonstrating the client''s informed consent to the engagement letter (article 151 of the Code of Ethics) and establishing the authenticity of certificates issued under article L823-12-1 of the Commercial Code.

Certyneo delivers for each signature an audit certificate integrated into the PDF, which brings together technical evidence:

Identity of the signatory (email + phone number verified by OTP)
Qualified timestamp of each action (send, view, sign, refuse)
SHA-256 cryptographic fingerprint of the signed document
IP and rough geolocation of the signatory at the time of signature
Detailed log of reminders and notifications

This bundle of evidence meets the requirements of article 1366 of the Civil Code (probative force of electronic writing) and is recognized by French case law (Cass. com., 13 March 2019). For certificates addressed to a third party (bank, URSSAF, landlord), the audit trail provides proof of authenticity of the document issued by the firm.

OEC compliance, Commercial Code and eIDAS

Certyneo is part of the legal and ethical framework applicable to the accounting profession.

OEC Code of Ethics

Article 151 of the Code of Ethics requires a written engagement letter prior to any service. Article 145 governs the confidentiality of client data. Certyneo applies end-to-end encryption and archiving with probative value compatible with these obligations.

Commercial Code — art. L123-12 and L823-12-1

Article L123-12 sets the accounting obligations of merchants; article L823-12-1 governs certificates issued by statutory auditors. Certyneo''s advanced signature meets the authenticity and integrity requirements of these provisions.

Labor Code — art. L3243-2 (pay stub)

Since the Macron law of 6 August 2015, the employer may provide the pay stub in electronic form under conditions guaranteeing its integrity, its availability for 50 years (or until the employee reaches age 75) and the confidentiality of data.

Article 1366 of the Civil Code & eIDAS regulation

Electronic writing has the same probative force as paper writing if the identity of the signatory can be duly established and the integrity of the document is guaranteed. Certyneo''s advanced signature (AES) meets these two requirements under regulation (EU) no. 910/2014.

Electronic signature guide·eIDAS guide·Certyneo security·Free contract templates

Frequently asked questions from accounting firms

Can a letter of appointment as an expert accountant be signed electronically?

The Certyneo advanced signature (AES) fulfils the probative requirement, with the advantage of precisely timing the acceptance of the fee and the scope of the assignment BEFORE the service begins.

What is the value of an electronically signed certification of expert accountant in front of a bank?

A certificate signed electronically with AES level (Certyneo) has the same value as a hand-signed stamped paper certificate. The recipient (bank, URSSAF, landlord) can check the audit trail from the verification URL included in the PDF certificate he sees the identity of the signatory, the date, and the absence of alteration of the document.

Is the dematerialized payroll taxable for all employees?

Since the Macron law (1 January 2017), the employer can issue the bulletin electronically without the employee's prior consent, provided that the employee has been informed at least one month in advance and that the retention conditions are met (50 years or up to the employee's 75th birthday).

How long does a letter of assignment take to keep?

Article L123-22 of the Commercial Code requires that accounting records be kept for 10 years. For prudence's sake, the same period applies to letters of business, which serve as proof of the acceptance of fees in case of litigation.

Does Certyneo integrate with my accounting production software?

A public REST API is available with event webhooks (envelope.signed, recipient.signed, etc.) Native integrations with the main accounting software (CEGID, ACD, RCA, ISACOMPTA, QuadraCompta) are being deployed. Contact us for the exact status of your solution.

Is the professional secrecy of the accountant respected?

Oui. Certyneo applique un chiffrement TLS 1.3 en transit et AES-256 au repos, une isolation stricte par cabinet, et un hébergement 100 % UE (Allemagne, IONOS) sans sous-traitance hors UE. Une DPA conforme GDPR est disponible et intègre les clauses spécifiques au secret professionnel de l'article 8 de l'ordonnance 45-2138.

Can we get a joint venture agreement signed by multiple partners by electronic signature?

Certyneo manages the serial or parallel signatures between multiple signatories natively. Each partner receives their personal link with OTP SMS on their own number. The single audit trail gathers all signatures and time stamps, which facilitates the keeping of the digital PV register.

How much does an electronic signature cost for an accounting firm?

A free plan allows testing on 5 envelopes per month. Beyond that, paid plans start at a rate compatible with customer billing (re-billing possible). The rate includes 10-year archiving, eIDAS trail auditing and technical support.

Sign your next engagement letter in 5 minutes

Create your free account and test the Certyneo audit trail on a real engagement letter. No credit card, no commitment.