Micro-business vs real BNC regime simulator
Compare the French micro-BNC regime with the real BNC regime using your revenue, actual expenses and accounting costs.
Compare micro-BNC taxable base with real profit after deductible expenses.
Include indicative social charges and accounting costs.
Spot cases where a full BNC filing review is needed.
Micro-BNC or real regime: the key variable is actual expenses
The micro-BNC regime is simple, but the flat allowance can become unfavourable when professional expenses, equipment, subcontracting or training costs increase. The real regime requires stronger bookkeeping, but it aligns taxable profit with economic reality.
Micro-BNC
Micro-BNC applies a flat allowance to revenue. It is simple, but actual expenses are not deducted one by one.
- Useful for lean activities with limited costs.
- Less attractive when recurring expenses increase.
- Needs monitoring as revenue approaches applicable thresholds.
Real BNC regime
The real regime allows justified expenses to be deducted. It requires bookkeeping and professional filing, but gives a clearer view of the business.
- Relevant when actual expenses exceed the flat allowance.
- Useful to monitor margin, VAT, cash flow and investments.
- Requires evidence and regular accounting discipline.
Tax decision
The simulator does not only compare tax. It also shows whether the extra administration brings better management value.
- Compare potential tax benefit with fees and admin time.
- Anticipate VAT, social charges, CFE and protection.
- Document expenses before changing regime.
Inputs to prepare
The comparison becomes reliable only when expenses are documented. Without evidence, the real regime may lose practical value.
- Annual collected revenue and next-year forecast.
- Actual costs: equipment, software, travel, rent, insurance and training.
- Accounting fees, software cost and administrative time.
- VAT status, threshold monitoring and cash-flow needs.
Hayot Expertise analysis
We recommend avoiding a decision based only on headline rates. The real BNC regime becomes useful when expenses are recurring, VAT enters the model or the professional wants proper business management.
The underestimated risk
Underestimating actual expenses can keep you in the micro regime too long. Switching to the real regime without evidence, workflows and projections can create excessive administration.
What the professional must decide
- The sustainable level of actual expenses.
- Whether VAT recovery and monitoring matter.
- The acceptable cost of bookkeeping and filing.
- The right date for switching regimes.
2026 watchpoints
- Check current thresholds and options before switching.
- Keep complete evidence for every deducted expense.
- Do not confuse taxable profit with available cash.
- Anticipate social charge adjustments after income changes.
Micro-BNC and real BNC FAQ
When does the real BNC regime become attractive?
It deserves review when documented actual expenses exceed the flat allowance or when you need better margin and cash-flow management.
Does the simulator calculate exact personal income tax?
No. It compares indicative bases and charges. Final tax depends on household income, options and personal facts.
Is the professional BNC filing required under the real regime?
The real regime implies detailed professional reporting. The exact filing process must be validated for your activity.
Are social charges final in the simulator?
No. The model uses indicative rates to support the decision. Actual calls and adjustments must follow current URSSAF rules.
Can you return to the micro regime later?
Options and timing need to be checked before switching. A regime change should be projected over at least two financial years.
Official sources
Updated on 4 May 2026. Results are indicative and do not replace a tailored filing review.
Go further
Need to know whether the real BNC regime is worth it?
We can review your revenue, expenses and filing calendar to choose a regime that fits your tax position and operations.