How do you get a tax number and file taxes in Belgium in 2026?

Your national register number is the key for MyMinfin, Tax-on-Web, and most payroll withholding. You receive it through commune registration after the police residence check, not through a separate tax-office queue: Register address. Non-residents sometimes use a BIS number for limited situations; ordinary settlers living in Belgium use the National Register path.

Open MyMinfin when you have eID or itsme access: Get an eID and Set up itsme. Employers already withhold tax from Belgian salaries; that does not cancel the annual return. Build household budgets from net pay: Monthly budget and How expensive is Belgium.

SPF Finances typically invites residents to file each spring or early summer. Many people use Tax-on-Web with a pre-filled proposal; paper forms still appear for some households. Deadlines differ for paper versus online filing, so read the year’s invitation rather than a forum rumour. Keep Belgian IBAN details ready for refunds or payments: Open a bank account.

Special regimes for some qualifying newcomers exist under separate FPS Finance rules and tight application windows after starting work. Treat those as optional specialist files, not as a reason to skip ordinary registration. Residence permission remains Immigration’s track: Residence permit. Mutualité membership is healthcare, not tax: Choose health insurance.