The pre-filled tax return — how to check and what to add?

The pre-filled return (VIA, online from 1 March) contains by default: (a) payroll from employer/benefit body; (b) Box 3 assets per 1 January (banks, investment accounts automatic); (c) Mortgage data (interest + WOZ); (d) AOW + pension; (e) Tax credit table. WHAT MISSING:

1. Deductions like donations, periodic church, alimony paid, medical above threshold
2. Side income as freelancer, marketplace sales > threshold
3. Foreign income (overseas real estate, dividend)
4. Gifts and inheritances (separate return)
5. Undisclosed bank accounts (increasingly auto-reported via EU CRS)
6. Mortgage cancellation or early repayment in current year. Return deadline1 May year after, can extend to 1 September on request. Key: AGREEING to VIA = you sign that all is correct. On post-audit increase YOU are responsible, not the Tax Office.