Chartered Accountant for Engineering Consultancies (BET)

A bureau d'études techniques is a professional services firm that designs, calculates and specifies on behalf of a client or another builder, without carrying out the works itself. It is also called an engineering firm or a firm of consulting engineers (ingénieurs-conseils). Its engagements are sold on a fixed-price or time basis, run over several months and generally fall under the Syntec collective agreement (IDCC 1486).

An accountant for such a firm works on four points that general bookkeeping does not settle on its own:

• revenue recognition, on completion or as the contract progresses, with the work in progress and accrued income that follow;
• the research tax credit base and the JEI research-spending threshold, built from time recorded project by project rather than from invoices issued;
• the price revision clause, indexed on the Syntec index, which protects the margin only if it is calculated and invoiced at each due date;
• margin per project, the only reading that tells you whether a contract won was actually profitable.

Bookkeeping, tax and payroll under the Syntec agreement follow.

These four professions are often confused, although they share neither the same billing model nor the same accounting risks. A bureau d'études techniques sells an intellectual engineering service: calculation notes, sizing, structure, building services, thermal studies, industrial process. It commits engineer hours to a technical deliverable, usually for a fixed price, on assignments that run several months and cross the year end. Fixed price plus duration: that combination triggers everything below.

A BET is not a construction company: everything that touches the building site (multiple VAT rates on works, reverse charge on subcontracting, retention money, the industry holiday fund) belongs to the construction sector, and a construction-site chart of accounts answers none of a consultancy's real questions.

A BET signs a fixed-price study, invoices it against a negotiated schedule (on order, on the preliminary design, on delivery), and its year ends in the middle. The revenue of the year is neither what was invoiced nor what was collected: it depends on the method chosen for long-term contracts.

The Plan comptable général (PCG), the French general chart of accounts (ANC regulation 2014-03) and the source of French GAAP, treats these as long-term contracts, in articles 622-1 and following.

The starting point is Article 622-2: a long-term contract is accounted for either under the completed-contract method or under the percentage-of-completion method. That is a choice made by the entity, not an obligation, and as at 1 January 2026 the percentage-of-completion method is not one of the PCG's reference methods (méthodes de référence). Article 622-3 therefore applies only if you have opted for percentage of completion: in that case, and where the outcome at completion can be estimated reliably, the result is recognised by applying the percentage of completion to the outcome at completion, so revenue and margin follow the pace at which the study is actually produced. Article 622-4 organises the fallback: where the outcome cannot be estimated reliably, no profit is recognised and revenue is limited to the costs that contributed to performing the contract. The case for percentage of completion is one of management reporting and bank readability, not an accounting requirement.

Is the outcome reliably estimated? Article 622-5 gives three criteria:

1. the ability to identify clearly the total revenue of the contract;
2. the ability to identify clearly the total costs attributable to the contract;
3. the existence of management tools, cost accounting and internal control allowing the percentage of completion to be validated and the estimates of costs, revenue and outcome to be revised as the contract progresses.

Our reading. The third criterion is the one nobody reads and everybody suffers: it does not ask for an intention, it asks for a tool. Without project-level cost accounting and time sheets posted by engineer and by contract, a consultancy cannot justify a percentage of completion: it falls into article 622-4, margin flattened to zero on every open contract at the year end. Those same time sheets carry the research tax credit base. One failure, time not posted to a project, brings down both.

Two accounts carry the weight, under their French names in the trial balance. Travaux en cours (TEC), work in progress, records production carried out and not yet recognised as revenue, at production cost and never at selling price. Factures à établir (FAE), accrued income, records revenue earned, matching genuine progress, but not yet invoiced. Symmetrically, deferred income (produits constatés d'avance) neutralises an instalment invoiced ahead of the work actually done. An English-speaking reader should note that both sit on the balance sheet, and that it is their movement across the year end, not the invoicing schedule, that drives the revenue figure. The decision to adopt percentage of completion covers every contract in progress at that date (article 622-7), and the method is disclosed in the notes to the accounts.

One mechanism deserves particular attention, because it is the only one that brings the loss on a loss-making engagement into the accounts before delivery: the provision for a loss at completion (provision pour perte à terminaison). As soon as an overall loss becomes probable on a contract, meaning its total estimated cost at completion exceeds the total contract price, article 622-6 of the PCG requires that overall loss to be provisioned, less any loss already recognised, not merely the portion of the current year, whether the firm uses the completed-contract or the percentage-of-completion method. The provision is booked to account 1516, provisions for losses on contracts. A drifting fixed price thus weighs on the result as soon as its loss becomes probable, not at delivery.

The underestimated risk is not tax, it is banking: the completed-contract method gives a saw-tooth result, hostage to the delivery date of two or three contracts, and the banker reads volatility.

A worked example: the same contract under both methods#

An engineering assignment is sold for €80,000 excluding VAT. Its production cost is estimated at €56,000, so the outcome at completion is €24,000. At the year end, the time recorded and the costs incurred on the job total €21,000, so the contract is 37.5% complete (21,000 / 56,000), measured on costs as article 622-3 allows.

Under percentage of completion, what has already been invoiced is compared with the revenue recognised. If the firm has already booked €40,000 of milestone invoices as revenue, the €10,000 excess is neutralised as deferred income (produits constatés d'avance, account 487). If it has invoiced only €12,000, the missing €18,000 is booked as accrued income (factures à établir, account 4181). Under the completed-contract method, the €21,000 of costs are carried as work in progress (account 34) and the result waits for delivery.

For a supply of services, VAT is due on collection by default, and exigibility on the debits exists only by option (French tax code, CGI article 269-2-c). An engineering firm therefore remits the tax only once it has been paid, unless it has expressly opted for the debits, in which case the tax becomes due on invoicing.

This combines with percentage-of-completion recognition: accrued income is not an invoice. Under the default regime, VAT on collection, revenue booked as FAE at the year end makes no VAT due until the client pays. Under the debits option, chargeability follows the debit of the client account, which in practice coincides with issuing the invoice (BOI-TVA-BASE-20-50-10); the VAT on accrued income is booked as pending, in account 44587. Confusing accounting progress with chargeability leads either to remitting a tax that is not due, or to forgetting one that is.

The collection-versus-debits choice depends first on how fast your clients really pay. The law sets ceilings, summarised in the table below; in practice payments run late, and the cash effect is measured on those real delays. Staying on collection protects cash: the tax is remitted only once the client has paid. Opting for the debits simplifies the follow-up and lets a B2B client deduct on receipt of the invoice, but advances the VAT before collection. In every case, a deposit collected makes the VAT due immediately, even on the debits.

Penalties and sanctions are detailed in our article on payment terms between businesses.

The e-invoicing reform enters that choice. Since 1 September 2026, every VAT-registered engineering firm must be able to receive electronic invoices, whatever its size. Issuing electronic invoices and reporting transaction data apply at that date to large and mid-sized companies only: for SMEs and micro-businesses they start on 1 September 2027. The VAT timing choice weighs here too: for a service whose VAT is due on collection, the firm will have to report the date and amount of each payment received (the "Encaissée" status of an electronic invoice, or a payment-data flow), whereas opting for the debits removes that obligation. We size the cash effect against the simplicity before any option is filed.

From 1 January 2027, the VAT rules move from the French general tax code (CGI) to the code of taxes on goods and services (CIBS), with substance largely unchanged; references to the CGI remain accepted on invoices and contracts until 30 June 2028.

The Syntec index is published monthly by the Fédération Syntec, the French federation of engineering, digital and consulting firms. Contrary to a widespread belief, it is not published by INSEE, the national statistics institute: confusing the two produces clauses that cannot be applied.

It measures the cost of essentially intellectual labour, which makes it the natural index of an engineering contract, used contractually for price revision. The usual formula is P1 = P0 x (S1 / S0), S0 being the reference index at signature and S1 the index of the revision month. The Fédération Syntec now publishes a revised index whose reference point is December 2019; the link with the former index was made in August 2022 through a coefficient of 0.97975 (280.6 / 286.4), to be applied to the revised index for a contract signed before that date. Check the index base before calculating. As a benchmark, the revised index for August 2026, published on 30 September 2026, stands at 320.4, or 313.9 after linking for a contract signed before August 2022.

A BET signs a multi-year study in year N on a given engineer cost, and delivers in year N+2 with salaries that have risen meanwhile. Without a revision clause, wage inflation comes out of its margin. Three failures are possible: no clause, a clause never applied for lack of follow-up, or a clause drafted on an index that does not exist. Price revision is a margin item: calculate it, invoice it, monitor it.

The crédit d'impôt recherche (CIR) is the French research tax credit, offset against corporate income tax. For a BET it is both an opportunity and a trap: the activity produces technical knowledge, but the service sold to the client is not, in itself, research. What qualifies is the removal of a scientific or technical obstacle, not the application, however skilled, of known methods to a client project. Separating the two in the recorded time is the only way to make the base defensible. Beside it, the crédit d'impôt innovation (CII) covers prototypes and pilots of new products.

The parameters as at 1 January 2026 (French tax code, CGI article 244 quater B):

Two changes must be built into the calculation, or the credit is overstated. The flat-rate overhead allowance on staff costs fell from 43% to 40% for expenditure incurred since 15 February 2025. Several items have also left the base: patent filing, maintenance and defence costs, technology watch (previously capped at €60,000), and the doubling of the base for young doctorate holders. The Finance Act for 2026 maintained the scheme, without reforming the rates.

One confusion deserves to be denied without hedging, because it circulates as far as investor business plans: there is no enhanced CIR rate attached to JEI status. The only enhanced rates are geographic; for the CII they concern the overseas departments (60%) and Corsica (35% or 40%). A consultancy that builds its cash forecast on a "JEI-boosted" credit will discover the gap when the refund arrives.

Size it up with our CIR and JEI simulator. Our innovation funding assignment covers the accounting and tax side of the credit: the base, time tracking, the calculation and form 2069-A-SD, consistent with percentage-of-completion revenue. The technical file (state of the art, obstacles, work carried out) is written by your engineers or by a specialist firm.

A BET has a feature that sets it apart from a laboratory or a software publisher: on the same day, its engineers work on billable client assignments and, sometimes, on removing a technical obstacle. Both come out of the same minds, the same offices and the same time sheets. That porosity is exactly what makes the base fragile when it is not traced.

The border between the assignment and the research. A fixed-price study, however technically demanding, remains the application of known methods to a particular case: difficulty alone does not make it eligible. What is eligible is the work carried out to remove a scientific or technical uncertainty that the state of the art does not allow you to resolve, in the sense of the Frascati Manual, the OECD reference the tax authority relies on to assess this kind of obstacle. A consultancy that declares a percentage of its engineering revenue, without having isolated the corresponding hours, is presenting a base it will not be able to defend.

Hours, not invoices. The base is built from staff costs allocated to research, increased by the flat-rate overhead allowance (75% of depreciation charges and 40% of staff costs). The starting point is therefore a record of time by engineer, by project and by type of task, kept continuously. Reconstructing hours from memory at the year end, a few weeks before the tax return is filed, is the scenario that ends badly.

A base that has changed. One reservation before giving up a real cost item: the patent costs removed from the research tax credit base, like plant variety certificate and design costs, remain taken into account under the innovation tax credit (CII) for micro, small and medium-sized enterprises within the meaning of the EU regulation, within the shared cap of €400,000 a year and for expenditure incurred up to 31 December 2027. A file rolled forward from one year to the next, without picking up the changes made by the Finance Act for 2025, overstates the credit and manufactures its own reassessment. The credit is declared on form 2069-A-SD, filed electronically, for a company subject to corporate income tax, by the deadline of the balance statement no. 2572.

An engineering firm doing research for its clients. A company can include in its own research tax credit the cost of research it entrusts to a body approved by the ministry in charge of research (CGI, art. 244 quater B, II d bis). For an engineering firm, approval opens a commercial door, with one condition: the same expense counts only once. The approved firm excludes from its own base the expenses incurred for that work, unless its client cannot benefit from the credit, a foreign company for instance (BOI-BIC-RICI-10-10-30-20). On the client's side, these expenses count up to three times its other research expenses and €2 million a year, raised to €10 million where there is no dependency link. Approval is granted by the ministry, in principle for three years, on an application filed through its CIROCO tool; the 2025 CIR guide reported an average processing time of eight months.

The tax ruling, before committing the spending. When a project's eligibility is debatable, the research tax credit ruling (rescrit CIR) lets you ask the tax authority in advance (book of tax procedures, art. L. 80 B, 3°). The request must be filed at least six months before the deadline for the special return, that is by 15 November for a company subject to corporate income tax whose financial year is the calendar year; if no reasoned answer comes within three months, the authority is deemed to have agreed.

The jeune entreprise innovante (JEI) is the French young innovative company status (CGI, article 44 sexies-0 A). It is within reach of many consultancies, provided you reason on the current regime, not the one still described online.

The expenditure condition is now a minimum of 20% of the year's tax-deductible expenses devoted to research. The former threshold of 15% applies only to financial years ended before 1 March 2025. Between 5% and 20% of research and development expenditure, the company falls under the jeune entreprise de croissance (JEC) status, which adds a condition on economic performance indicators. Other conditions: under eight years old (the age condition for companies created since 1 January 2023), a European-sense SME (fewer than 250 employees, turnover below €50 million or balance sheet below €43 million), capital at least half held by individuals, no creation by concentration or restructuring.

The benefit has changed nature. The exemption from corporate income tax is abolished for JEI companies created on or after 1 January 2024. What survives, and matters for a BET whose engineer salaries make up most of its costs, is the exemption from employer social security contributions (social insurance and family allowances) on staff assigned to research, within a double cap: 4.5 times the minimum wage per employee (€8,401.58 per month) and 5 times the annual social security ceiling per establishment (€240,300 a year, for a 2026 ceiling of €48,060). This social exemption stays open to companies created before 31 December 2028, and the Finance Act for 2026 (article 40) extended to the same date the local business-tax and property-tax exemptions that local authorities may grant. A consultancy incorporated in 2026 is therefore still eligible, contrary to a widespread claim that closed the window at the end of 2025.

The research tax credit and JEI status can be combined: one works on tax, the other on payroll. Documented properly, the combination changes the cash trajectory of a young consultancy.

BETs generally fall under the Syntec collective agreement (IDCC 1486), and their engineers are often on a forfait annuel en jours, an annual fixed number of working days rather than counted hours. The point specific to a BET: the fixed-day contract removes the need to count hours, not the need to track time spent per project. Two different objects: one from employment law, the other from article 622-5 of the PCG and the credit base. The director who says "my engineers are on fixed-day contracts, so I do not track time" loses both.

The NAF activity code assigned by INSEE, the national statistics institute, does not decide the collective agreement: the agreement that applies is the one covering the employer's actual main activity (labour code, art. L. 2261-2), and the code is only an indication. The classification files neighbouring trades under separate codes:

A new classification, NAF 2025, comes into force on 1 January 2027 (decree no. 2025-736 of 31 July 2025): the code assigned will then need checking again. Any doubt about the main activity should be settled before the first hire: it drives minimum salaries, the conditions of fixed-day contracts and the provident scheme.

The statutory accounts of an engineering consultancy say very little that is useful. Margin is won or lost project by project, on contracts whose drift nobody measures before delivery. The earliest warning is the gap between cost progress and technical progress: a fixed-price job that has used 60% of its hour budget for 40% of its deliverables calls for a decision before delivery, not after. The eight indicators shown further down this page, in the steering cards, are the ones we put in place; none of them exists in a standard chart of accounts.

• Invoicing treated as recognition. Revenue follows the invoicing schedule, not real progress: the result becomes an artefact of the negotiation.
• Declarative time sheets, filled in at month end from memory. They validate neither the completion percentage nor the credit base, and do not survive an audit.
• A credit base modelled on the engineering invoiced to the client, booked wholesale as research: the sector's most predictable reassessment.
• A flat-rate overhead allowance still taken at 43%, when it has been 40% since 15 February 2025, or a base still holding patent costs and technology watch.
• A Syntec revision clause never activated, or indexed on an index that does not exist.
• Work in progress valued at selling price instead of production cost, which books a margin not yet earned.

Many engineering firms start with a single engineer working in their own name. Three frameworks coexist; the right one depends on turnover, investment and plans to hire.

As a self-employed professional, a consulting engineer contributes to the CIPAV fund for retirement and invalidity-death cover. Incorporating becomes relevant when you need to hire, invest or keep profits in the business; we model it on your figures before any decision. For consulting work with no engineering content, our page for consultants is the better fit.

Our fees depend on the structure (sole engineering consultant or company), the volume, and high-value work such as the research tax credit. They are set in the engagement letter, with no surprises.

A costed quotation is sent within 24 to 48 working hours after receipt of the documents requested.

Our conviction. In an engineering firm, everything hinges on a single discipline: posting time to each engagement. It is what allows percentage-of-completion recognition under French GAAP, what builds a defensible research tax credit base, what makes margin readable project by project. One and the same slackening brings down all three. Our job is not to keep accurate books once a year, it is to install, from the order letter onward, the setup that turns your accounts into a decision tool rather than a late statement of fact.

The firm is led by Samuel Hayot, a chartered accountant (expert-comptable) registered with the Ordre des experts-comptables of Paris Île-de-France, and a statutory auditor (commissaire aux comptes) registered on the list drawn up by the Haute autorité de l'audit (H2A) and a member of the Compagnie régionale des commissaires aux comptes de Paris. Cabinet Hayot Expertise, 58 rue de Monceau, 75008 Paris.

In concrete terms: project-level cost accounting and time tracking, revenue recognised as contracts progress with the documentation required by article 622-5, TEC and FAE at the year end, accounting and tax framing of the CIR and CII, JEI conditions and the employer contributions exemption, price revision through the Syntec index, plus bookkeeping, tax and payroll.

A first conversation is enough to say, on your documents, whether your open contracts are recognised correctly and whether your time tracking satisfies both the PCG and the tax credit.

The question arises for any building-sector engineering firm, and the answer is not uniform. The presumption of decennial liability under Articles 1792 and following of the French Civil Code falls on builders, and Article 1792-1 counts among them "any architect, contractor, technician or other person bound to the client by a contract for services". Two conditions therefore combine: acting as a technician on the works, and being bound to the client by a contract for services.

What follows in practice: an engineering firm designing a structure, building services or a technical installation under a contract with the client falls within the scope, together with the insurance obligation that comes with it. A firm working as a subcontractor to another builder, with no direct contract with the client, or whose engagement does not bear on the works themselves, does not fall within it in the same way. The distinction is read in the contract, not in the description of the activity, and it drives both the insurance premium and the provisioning of disputes.

Updated 2 October 2026. Informational content reviewed by a chartered accountant registered with the Ordre des experts-comptables of Paris Île-de-France.