💸 Can I work cash-in-hand?

Quick answer

No, working cash-in-hand is forbidden — it is illegal for both the worker and the employer. Undeclared work is work not declared to social security: no Dimona declaration, no social-security contributions, income hidden from the tax office. It differs from a genuine favour between friends (spontaneous, occasional, unpaid help), from volunteering, and from regulated association work (art. 17). As a worker you build no social rights (no pension, no health cover), and if you combine it with a benefit you must repay it (the unemployment office recovers up to 3 years back, 5 in case of fraud) and risk a fine and back-tax. For the employer, a missing Dimona is a level-4 offence under the Social Criminal Code: since 1 February 2026 (surcharges ×10) a criminal fine of €6,000 to €60,000 or an administrative one of €3,000 to €30,000, per worker involved, with possible imprisonment.

📋 The rules

Undeclared work = work not declared to social security (no Dimona, no contributions) — illegal
Different from a genuine favour between friends, volunteering or association work (art. 17)
Worker: builds no social rights; combined with a benefit, you must repay it
Recovery of benefits: up to 3 years back, 5 years in case of fraud
Employer: a missing Dimona = level-4 offence, a fine per worker
Since 1 February 2026 (surcharges ×10): level 4 = €6,000–€60,000 criminal / €3,000–€30,000 administrative

🔓 Exceptions

A spontaneous, occasional and unpaid favour between acquaintances is not undeclared work
Volunteering (with capped expense reimbursement) and association work (art. 17) are legal, regulated alternatives
There is no threshold for 'small jobs': one-off or occasional paid work without a Dimona declaration is undeclared work too

⚠️ Penalties & fines

For the employer, undeclared work is a level-4 offence under the Social Criminal Code: since 1 February 2026, a criminal fine of €6,000 to €60,000 or an administrative one of €3,000 to €30,000, multiplied by the number of workers involved, plus possibly 6 months to 3 years' imprisonment and the loss of social-security reductions. The worker does not get off either: wrongly received benefits must be repaid (up to 3 years back, 5 in case of fraud), you can be fined yourself, and meanwhile you build no pension or health-cover rights at all.

📎 Official sources

Last verified: 2026-07-12

❓ Frequently asked

Can I do the odd bit of cash-in-hand work?

No. Paid work not declared to social security is undeclared work, even occasional or one-off. A spontaneous, unpaid favour between acquaintances, on the other hand, is entirely allowed.

What do I risk as a worker?

If you combine undeclared work with a benefit, you must repay it: the unemployment office claws back up to 3 years, 5 years in case of fraud. A fine and back-tax can follow — the sanction does not only hit your employer.

Do I build social rights with undeclared work?

No. Without a declaration to social security your hours count nowhere: no pension build-up, no health cover, no work-accident insurance. Work undeclared for years and you end up empty-handed.

What does the employer risk?

A missing Dimona is a level-4 offence: since 1 February 2026, a fine of €6,000 to €60,000 (criminal) or €3,000 to €30,000 (administrative) per worker involved, with possible imprisonment on top.

Is there a legal alternative?

Yes: volunteering with a capped expense reimbursement, or association work (art. 17) for sport and socio-cultural activities. These come with their own limits and formalities, so check them beforehand.

🔎 Common searches

What people search to land here:

“undeclared work belgium illegal”
“undeclared work fine employer”
“undeclared work repay benefit”
“favour between friends or undeclared work”
“missing dimona sanction”
“undeclared work pension rights”