Belgium Freelancer — PB/IPP & BTW Return (Self-Employed)

Confirm the client is a Belgian resident natural person (not a BV/NV/CV) filing personenbelasting (PB/IPP) via Tax-on-web. Establish the income year (calendar year), assessment year (income year + 1), municipality of residence (required for gemeentebelasting), marital/family status, and any other income streams (employment, rental, investment) that fall outside the self-employment scope.

Gather all source documents needed for the return: full-year bank statement(s) from Belgian banks (BNP Paribas Fortis, KBC, Belfius, ING Belgium, Argenta) or neobanks (N26, Revolut) in CSV/PDF/CODA format, quarterly sociale bijdragen statements from the client's social insurance fund, VAPZ/PLCI contribution certificates, any fiche 281.10 for mixed employment income, and prior-year aanslagbiljet to verify opening voorafbetaling credits.

Classify every bank statement line as beroepsinkomsten, fully deductible beroepskosten, partially deductible (restaurant meals at 69%, business gifts at 50%, vehicle fuel capped at 75%), capitale uitgaven subject to afschrijvingen, or personal/excluded items. Apply the Belgian transaction pattern library: identify BTW-registered gross receipts and strip out the BTW component so only the net amount enters beroepsinkomsten. Flag vehicle transactions for CO2-based deductibility calculation.

Compare the two mutually exclusive expense methods — werkelijke (actual documented expenses including sociale bijdragen) vs forfaitaire beroepskosten (graduated flat-rate scale, max ~EUR 5,750 for AY 2026) — and elect the more favourable method. Deduct sociale bijdragen in full under either method. Verify VAPZ/PLCI contributions against the statutory cap (gewoon: 8.17% of reference income, max ~EUR 3,965; sociaal: 9.40%, max ~EUR 4,562, reference income = net professional income 3 years prior).

Calculate net taxable professional income (beroepsinkomsten minus elected beroepskosten). Apply the progressive PB/IPP brackets for AY 2026 (25% up to EUR 16,720 / 40% to EUR 29,510 / 45% to EUR 51,070 / 50% above). Apply the belastingvrij minimum as a tax reduction at 25%: base EUR 10,910 (= EUR 2,727.50 reduction), increased for dependants. Then compute the gemeentebelasting surcharge using the client's exact municipal rate.

Reconcile any voorafbetalingen (advance tax payments) made via MyMinfin against the four quarterly deadlines (VA1 10 April 12% benefit, VA2 10 July 10%, VA3 10 October 8%, VA4 20 December 6%). If insufficient advance payments were made, calculate the vermeerdering (surcharge, approximately 9% of tax due for AY 2026). Identify whether any bonification credits offset the surcharge. Advise on whether additional voorafbetalingen are advisable before the VA4 deadline.

Prepare the final Tax-on-web (MyMinfin) submission: populate the relevant codes in the personenbelasting (PB/IPP) return — principally frame II (beroepsinkomsten), frame IV (deductible expenses if using actual method), and any applicable reduction frames. Confirm the filing deadline (30 June self-filing, mid-October via accountant). After submission, explain how to read the aanslagbiljet (tax assessment) when it arrives and what to do if the client disagrees (bezwaarschrift within 3 months).