The developer’s expense list: hardware, home office, and the deduction that is smaller than you think

Deductions are not refunds

The single most common mistake is treating a deduction like a discount. A deductible cost reduces your taxable base, so what it saves you is the cost multiplied by your tax rate — not the cost itself. A €3,000 laptop in a company taxed at 20% saves €600 of corporate tax. You are still €2,400 out of pocket. Buying hardware you do not need in order to “save tax” loses money in every case.

That framing matters because it puts the levers in the right order: the ones worth chasing are those that move money to you tax-free, not those that reduce a base you were going to be taxed on anyway.

The home-office allowance: the biggest one nobody claims

A one-person company can pay its director a monthly office lump sum free of tax and social contributions — €160.99 per month from 1 March 2026, which is €1,932 a year landing in your account untaxed. To pay yourself the same net through salary you would have to gross up through social contributions and personal tax, which is why the engine values this lever at €2,775 a year on the €132,000 profile.

It covers the costs of working from home structurally and regularly — heating, electricity, the room, small office supplies. It requires genuine, regular home working, which for a remote developer is not a stretch. It is a standing allowance, not a reimbursement of receipts, so there is nothing to collect.

The investment deduction, honestly

The investment deduction lets a small company deduct an extra percentage of qualifying new fixed assets on top of normal depreciation: a basic rate of 10%, or 20% for qualifying digital investments. It sounds generous until you follow the arithmetic.

On a €4,000 machine at the 20% digital rate, the extra deduction is €800 — and because a deduction saves you tax at your corporate rate rather than paying you back, it is worth €160. At the 10% basic rate it is €400 of deduction and €80 of saving. Worth claiming, since it costs nothing but a line in the return. Not worth timing a purchase around, and certainly not worth buying hardware you do not need.

The rest of the list

On the same modelled profile, the allowances and benefits available to a one-person BV rank roughly like this per year: meal vouchers €2,944, the home-office allowance €2,775, the bicycle allowance €1,293, and a general expense review €512. The vouchers and allowances beat the hardware deduction by an order of magnitude, because they move money to you without passing through income tax and social contributions at all.

• Hardware and peripherals — deductible, depreciated over their useful life; the VAT is deductible separately
• Software, cloud, domains, CI minutes, API bills — ordinary deductible costs, and easy to under-record because they are small and monthly
• Home internet and mobile — deductible in proportion to business use; a fixed private-use share is the usual treatment
• Professional training, conferences, technical books — deductible, and frequently forgotten
• Professional insurance and your accountant — deductible

The rule that keeps all of it safe

Business expenses must be incurred to obtain or keep taxable income, and you must be able to show it. For a developer, the awkward cases are the dual-use ones: the machine you also game on, the phone you also call your mother with, the conference in an attractive city. None of these are forbidden; all of them need a defensible business-use share and a paper trail. The mixed-use items are where reassessments start, not the obviously professional ones.