Add-backs and deductions: from accounting profit to taxable profit

Quick answer. The profit used as a tax base is not the figure in your income statement. You start from the accounting profit, add back non-deductible expenses, and deduct non-taxable income: taxable profit = accounting profit + add-backs - deductions. These extra-accounting adjustments are detailed on form 2058-A of the tax return package.

Every year, at closing, the same misunderstanding comes up in client files: a director sees an accounting profit of 50,000 €, expects tax calculated on that figure, and discovers a different tax base. Nothing is wrong. Accounting profit and taxable profit follow two distinct logics. Accounting reflects the economic reality of the period under the rules of the French accounting plan. Tax law applies its own rules of deductibility and taxation, which do not always match the bookkeeping.

The bridge between the two is called extra-accounting add-backs and deductions. These are adjustments that are not recorded in the accounts (hence the term « extra-accounting ») but are entered directly on the tax return package to move from accounting profit to the tax base. Understanding this mechanism means you stop enduring the gap between the two figures and start anticipating it.

Accounting profit is the difference between the income and expenses recorded for the period under the accounting framework. It reflects economic performance. But the tax authority does not allow every expense as a deduction, and does not tax every item of income the same way. Two families of differences therefore appear systematically.

First family: expenses recorded in the accounts, entirely regular from an accounting standpoint, that tax law refuses to allow as a deduction. They must be added back, that is, added to the result. The effect is positive: the tax base increases.

Second family: recorded income that must not be taxed, either because it has already been taxed elsewhere or because a favourable regime exempts it. It must be deducted, that is, subtracted from the result. The effect is negative: the tax base decreases.

The general formula fits in one line:

taxable profit = accounting profit + add-backs - deductions

This is exactly the mechanism reflected by form no. 2058-A (« determination of taxable profit ») of the tax return package, under the standard actual regime. Under the simplified actual regime, the reasoning is identical but is expressed on the 2033 series of forms, in particular form 2033-B. The logic does not change: you start from the accounting figure, you adjust, you obtain the tax figure.

Add-backs correspond to expenses recorded in the accounts but not deductible for tax purposes. Here are the most frequent in SME files.

A few points deserve clarification.

Corporate income tax. This is the most systematic add-back and the one that surprises directors most. Corporate tax is recorded as an expense, which reduces accounting profit, but the law (article 213 of the Tax Code) does not allow it as a deduction from its own base. It must therefore be added back. Mechanically, the tax base is calculated « before » tax.

Fines and penalties. Monetary sanctions and fines, in particular criminal ones, are not deductible (article 39, 2 of the Tax Code). A parking fine paid by the company, a late-payment penalty on a contribution: these are accounting expenses but must be added back.

Passenger vehicles. The depreciation of a passenger vehicle is only deductible up to a ceiling. The portion exceeding that ceiling is added back each year. The deductibility ceiling is set at 18,300 € in the general case, lowered to 9,900 € for the highest-emitting vehicles, and raised to 30,000 € for low-emission electric vehicles, depending on the CO2 emission rate (article 39, 4 of the Tax Code). This is a recurring adjustment, often forgotten in the first years after purchase.

Hayot Expertise tip. Keep a tracking table of add-backs from the moment you acquire a passenger vehicle. The non-deductible portion recurs identically every year until the end of the depreciation period. Calculating it once, then carrying it forward, avoids the most common and most audited mistake.

Deductions correspond to recorded income that is not taxable, or already taxed elsewhere. The three most frequent cases:

1. Dividends eligible for the parent-subsidiary regime. When a company holds a stake in a subsidiary, the dividends received can be subtracted from the result, with only a share of costs of 5 % remaining taxable (article 216 of the Tax Code). The regime requires the conditions of article 145: a stake of at least 5 % of the capital and holding the shares for at least 2 years.
2. Long-term capital gains on participation securities. They are exempt, subject to the add-back of a share of costs of 12 % (article 219, I-a quinquies of the Tax Code), for securities held for at least 2 years. The gain appears as accounting income but leaves the tax base, apart from the share of costs.
3. Carried-forward tax losses offset. A loss recorded in a prior period and carried forward can be offset against the profit, reducing the tax base of the period accordingly.

Let us take a fictitious company, for illustration only. The figures below are not legal thresholds but a textbook case to visualise the transition.

The lesson is immediate: an accounting profit of 60,000 € can lead to a tax base of 68,500 €, because the add-backs weighed more than the deduction. Conversely, a company with large parent-subsidiary dividends or exempt capital gains can show a taxable profit well below its accounting profit. Tax is never simply derived from the profit shown in the income statement.

Our reading#

Add-backs and deductions are not a technical footnote at the end of the return. They determine the actual amount of tax and, in many files, the gap between expected cash and cash available after paying corporate tax. A director who anticipates major add-backs (corporate tax, vehicle, any penalties) manages cash flow. One who discovers them at closing endures it.

The parent-subsidiary regime#

The parent-subsidiary regime is one of the most powerful deductions, but also one of the most regulated. The conditions of article 145 (a stake of at least 5 % of the capital, holding the shares for at least 2 years) must be met and documented. The share of costs of 5 % remains taxable: the exemption is therefore not total. In group structures and holding setups, this is a permanent verification point.

Long-term capital gains on participation securities#

The sale of participation securities held for at least 2 years falls under the long-term capital gains regime: exemption subject to the add-back of a share of costs of 12 % (article 219, I-a quinquies of the Tax Code). The qualification of the securities as « participation securities » and the holding period condition the benefit. A qualification error is costly.

Passenger vehicles#

This is the most ordinary and most overlooked specific case. As long as the vehicle is being depreciated, the portion exceeding the deductibility ceiling is added back each period. On a car acquired above the ceilings, this is an annual add-back spread over the entire depreciation period.

The underestimated risk#

The most frequent risk is not a calculation error: it is the plain omission of a recurring add-back, typically the non-deductible portion of a vehicle or a penalty buried in expenses. The entry is accounting-correct, so nothing raises a flag. It is precisely this kind of omission, repeated over several periods, that surfaces during an audit. Accounting regularity does not equal tax deductibility.

In a closing file, the sequence is always the same:

• Start from the trial balance and the final accounting profit.
• Identify the non-deductible expenses to add back (corporate tax, fines, vehicle portion, luxury expenses, share of costs on favourable-regime income).
• Identify the income to deduct (parent-subsidiary dividends net of share of costs, long-term gains net of share of costs, offsettable losses).
• Enter each line on form 2058-A (or 2033-B under the simplified actual regime).
• Obtain the taxable profit, the basis for calculating corporate tax.

This mechanism is best prepared ahead of closing, not discovered when filing the return. That is the purpose of good preparation between bookkeeping and accounting review and corporate tax work: identifying adjustments early in order to anticipate them.

• The distinction between accounting expense and deductible expense remains a stable principle: a properly recorded expense is not automatically deductible.
• Deductibility ceilings for passenger vehicles depend on the CO2 emission rate; check the applicable category for the vehicle before fixing the add-back.
• The parent-subsidiary regime and the long-term gains exemption require holding conditions to be documented: a poorly built file weakens the benefit.
• For sensitive figures (rates, thresholds, exact amounts), the detail depends on a file-specific analysis and the rules in force.