A future tax at sale may feel fairer, but only if owners can reconstruct what they bought and when.
The company accounts are reconciled, the VAT return has been filed, and salary records are in order. Then an owner opens a private brokerage account and finds ten years of investments, transfers and corporate actions reduced to one current balance.
The value is visible. The history is not.
That gap matters after the government’s latest Box 3 proposal. On 3 November 2026, the State Secretary of Finance sent an amendment to the Tweede Kamer. It proposes realisation-based taxation for financial instruments, including shares, bonds and options.
The proposal remains in parliament. Its practical meaning is already clear. When tax follows a sale or another realisation event, acquisition values, transaction dates and ownership history move to the centre of the private wealth file.
A portfolio statement can show what an owner holds today. It may say little about how that holding arrived there.
A different tax moment
The Wet werkelijk rendement box 3 aims to tax actual return. It separates direct return, such as interest, rent and dividends, from changes in asset value.
Its original design used annual taxation of value changes as the main approach. Specified assets would receive realisation-based treatment. The November amendment widens that second category by bringing financial instruments within it.
The result would remain a mixed system. Direct income would keep its annual rhythm. Gains on covered financial instruments would move towards taxation when the gain is realised.
The appeal is easy to understand. A tax charge at sale can feel closer to an owner’s economic experience than an annual charge on an unrealised increase. Paper wealth and cash are different things.
Yet a sale does not always leave free money in the bank. The proceeds may already have a purpose: debt repayment, a replacement investment, succession, or funding for another business venture.
The useful question is wider than when tax falls due. If this asset is sold, what does that decision release, postpone or constrain across private cash, company funding and family commitments?
Private wealth meets company cash
For an owner-manager, Box 3 is private, but its effects rarely stay outside the BV. A personal tax bill can lead to a dividend, higher salary, shareholder loan or unexpected call on company cash.
Each route has its own tax and legal character. None should arise by accident because the private side of the household lacks liquidity.
On paper, private assets and company assets sit in separate boxes. Around the kitchen table, they often support the same household, pension expectation and appetite for business risk. That is why a private investment file deserves much of the discipline given to a company ledger.
Classification matters as much as valuation. Shares and options sit in Box 3 only where they do not belong to a substantial interest or another tax category. A founder’s shares, an employee option, a family investment and an ordinary listed holding can look similar in a wealth overview while receiving very different treatment.
A hurried transaction is rarely a sound answer to a legislative proposal. Better preparation is quieter. Owners can map what they hold, where it is held, when it was acquired and which supporting records still exist.
Old broker transfers, share certificates, option agreements, merger notices, split records and conversion documents may later explain a number that now appears as one line on a screen.
The present system still matters
While parliament considers the future system, the transitional Box 3 regime remains in force. The Belastingdienst calculates tax using forfaitary returns, unless a taxpayer reports a lower actual return through the counter-evidence route.
Actual return includes income and annual value movements. It can cover interest, dividends and changes in the value of shares, second homes and crypto-assets.
For the 2026 preliminary assessment, the tax-free allowance is €59,357 per person, or €118,714 for fiscal partners together. The preliminary forfaitary returns are 1.28% for bank balances and cash, 6.00% for other assets and 2.70% for debts. The tax rate on calculated return is 36%.
These figures belong to the current system. They should sit separately from any future gain on disposal. An owner may need to understand three amounts at once: current private tax cash, this year’s economic return and a later taxable gain when an investment is sold.
Government information refers to an intended start in 2028 and entry into force no later than 1 January 2029. That makes record preparation timely. It does not justify building a private or corporate cash plan around one fixed date.
Good records protect good decisions
The owner looking at that brokerage balance does not need a grand restructuring this week. The immediate work is more modest and more valuable: reconstruct the investment history while banks, brokers, advisers and counterparties can still assist.
That work can strengthen the current counter-evidence position. It also clarifies where private wealth ends and company money begins. For many owner-managers, that boundary is the more important control question.
The proposal carries a simple lesson. Tax timing cannot repair weak ownership discipline. A realisation-based system may bring tax closer to the transaction that produces cash, but it requires a longer financial memory.
The sale is only the final event. Its relevant history may begin with an acquisition, transfer, inheritance, conversion, merger or option grant years earlier.
Box 3 is still moving. Owners do not need to chase every political turn. They do need records that can survive one.
When the system settles, the stronger position will belong to those who can explain what they own, how it arrived there and what the next decision means for both company and household.
If Box 3 may affect your private liquidity or company funding, review the ownership records and cash consequences before acting.
The data, sourcing, and analysis behind this article were conducted by Linda Pavan Geraedts. 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 Geraedts before publication.
References
- Wetsvoorstel novelle uitbreiding vermogenswinstbelasting box 3 - Taxence
- Rijksoverheid - November 2026 amendment expanding capital-gains treatment
- Overheid.nl Wetgevingskalender - Underlying design of the new Box 3 system
- Belastingdienst - Current transitional regime and actual-return counter-evidence
- Belastingdienst - Current 2026 Box 3 cash exposure
- Overheid.nl Wetgevingskalender
- Rijksoverheid
- Belastingdienst
