Private capital set aside for a future business project may still be private wealth for tax purposes. A plan alone does not give an investment a business function. For 2026, preliminary box 3 assessments use notional returns before the year’s actual return is known.
Why this matters
Asset classification affects the tax return, balance sheet and cash forecast. Money held for a property, acquisition or new location needs a documented business link. For private portfolios, the full box 3 result includes losses, interest, dividends, debts and value changes. A negative total actual return is set at zero and cannot be carried forward. A preliminary assessment may compete with VAT, payroll and supplier invoices before any correction is processed.
Example
A business owner plans to buy premises next year. She expects to sell shares from her private portfolio for the deposit. No property has been selected, and the business has made no funding decision. Her shares remain private. During 2026, the portfolio falls in value. That loss is not a business cost because the money may be used later. It belongs in the owner’s full box 3 calculation. Only money available to the business now belongs in its cash forecast.
XTROVERSO tips
- Separate private and business money. List each bank account, portfolio and debt. Record the legal owner and its current treatment in the accounts.
- Check the project file. Record the project, expected cost, current stage and next commitment. Add decisions, contracts and financing papers when they exist.
- Match reserves to the cash forecast. Show when the business expects to spend the money. A general intention does not replace a dated funding need.
- Build the full box 3 record. Keep bank statements, broker records, debt interest, dividends and annual valuations together. One losing portfolio is only part of the calculation.
- Plan for the preliminary assessment. Set aside enough private cash for the expected payment. Do not count a possible later tax correction as cash available today.
- Label every movement correctly. Record transfers as a withdrawal, capital contribution, loan or repayment. Check that the contract, bank entry and ledger tell the same story.
Need help reviewing private capital, project funding and box 3 payment timing? We can review your records and next steps
The data, sourcing, and analysis behind this article were conducted by Linda Pavan. AI was not used to identify sources, build the factual basis, or produce the analytical judgment contained here. AI was used only as a drafting aid. The final English text was personally reviewed, edited, and approved by Linda Pavan before publication.
References
- Taxence — Effectenverlies geen box 1 ondanks woningbouwplannen
- Rechtspraak — Official court record, ECLI:NL:RBGEL:2026:3032
- Belastingdienst — Business assets, private assets and surplus cash
- Belastingdienst — Annual records for entrepreneurs
- Belastingdienst — Calculating actual return in box 3
- Belastingdienst — Box 3 calculation for 2026
- Rijksoverheid — Timeline for the actual-return box 3 system
