Earning an additional 300 euros each month seems achievable when reading the lists of ideas circulating online. The gross amount displayed on a platform or an invoice from a micro-entrepreneur does not correspond to the actual amount received. Social contributions, income tax, platform fees, billing obligations: each item chips away at the income. This article measures what is actually left in your pocket when aiming for that 300 euros monthly threshold.
Micro-enterprise or platform: comparison of deductions on 300 euros gross
The choice of status or sales channel directly determines the retained share. Here is a synthetic comparison for a service activity (intellectual or manual services) declared in France.
| Channel | Social contributions | Platform commission | Tax (liberating payment) | Estimated net remaining |
|---|---|---|---|---|
| Micro-enterprise (services, normal rate) | About 22% of revenue | None | 1.7% to 2.2% of revenue if eligible | Around 228 euros |
| Micro-enterprise with ACRE (1st year) | Reduced rate (about half) | None | Same | Around 264 euros |
| Service platform (freelance type) | Variable depending on status | 5% to 20% depending on the platform | According to tax regime | Variable, often below 220 euros |
The ACRE line deserves special attention. The ACRE reform in 2026 changed the reduced rate, which alters the entry cost for anyone starting a side activity this year. Many articles list ideas for supplementary income without mentioning this development.
To delve deeper into concrete avenues that allow reaching this threshold, Slouppi’s advice details several methods suited to different profiles.
Hidden fees and obligations that reduce net income
The table above does not capture all expense items. Several costs go under the radar when starting a supplementary activity.
- The business property tax (CFE) applies from the second year of activity in a micro-enterprise. Its amount depends on the municipality, but it represents a fixed deduction that weighs more heavily on a small turnover.
- Bank fees related to a dedicated account (mandatory beyond a certain revenue threshold) add a few euros per month, sometimes more depending on the chosen institution.
- Freelance platforms take a commission on each assignment. Some platforms combine service fees and withdrawal fees, which can exceed the displayed commission alone.
- From September 1, 2026, auto-entrepreneurs must be able to receive electronic invoices via an appropriate platform. This is not a direct cost for everyone, but electronic invoicing becomes a compliance obligation as soon as one works with professional clients.
A service micro-entrepreneur invoicing 300 euros gross per month may therefore see their actual net income drop below 200 euros once these items are added, outside of the first year with ACRE.
The trap of the liberating tax payment
The liberating payment of income tax (between 1% and 2.2% of revenue depending on the nature of the activity) seems advantageous. It is only beneficial if the household’s reference tax income remains below a certain ceiling. Beyond that, opting for this regime means paying more than necessary. The choice of liberating payment must be recalculated each year based on the household’s total income.
Home and online activities: where is the best effort/net income ratio
Not all supplementary activities are equal when reasoning in terms of net income per hour invested. Three families stand out by their cost structure.
Intellectual services in micro-enterprise
Writing, translation, administrative assistance, accounting: these services generate few operating costs. The social contributions rate is that of BNC (about 22%), but there is neither stock nor platform commission if the client is found directly. The net income per hour worked remains the highest in this category, provided that billing is done without intermediaries.
Sale of products and resale of items
Reselling on marketplaces (clothing, items, equipment) benefits from a tax exemption for second-hand goods sold at a price lower than their purchase. However, as soon as the activity becomes regular or exceeds a certain volume, it falls under the micro-enterprise framework with associated contributions. The commissions of sales platforms range from a few percent to over 15% depending on the site.
Rental of goods (car, parking, housing)
Renting out an already owned asset allows for generating supplementary income with little recurring effort. Rental income is, however, subject to income tax and, in some cases, social contributions. Short-term furnished rentals have faced stricter taxation in recent years.
Revenue thresholds and ceilings to watch in 2026
The revenue ceiling for service activities in micro-enterprises has been raised to 83,600 euros for services in 2026. This threshold is well above the 3,600 euros per year that represent 300 euros per month, but two mechanisms remain to be monitored.
The first concerns the VAT exemption. It applies below a certain revenue threshold. As long as the activity remains modest, there is no VAT to charge or remit, which simplifies management.
The second concerns the accumulation with a salaried job. The employment contract may contain an exclusivity or non-compete clause. Checking this point before launching a side activity avoids legal complications unrelated to taxation.
Aiming for 300 euros net monthly actually requires invoicing between 370 and 420 euros gross depending on the status, fees, and tax regime chosen. The difference between the displayed gross and the net received explains why many abandon a supplementary activity after a few months: the actual return is lower than they anticipated. Doing the calculations before choosing a channel remains the best way to avoid working at a loss.
