The Law of 6 April 2026 does not impose FIFO: pre-2026 holdings follow a weighted average per asset. But transfers, wraps, staking rewards and the step-up basis cause four concrete mistakes that distort your taxable base.
Since 1 January 2026 you calculate your crypto capital gains according to the rules of the Law of 6 April 2026 (approved by the Chamber on 3 April 2026, published in the Belgian Official Gazette on 21 April 2026). But contrary to what is often claimed, that law does not impose FIFO. For crypto you already owned before 2026, a weighted average acquisition value per asset applies (art. 102 §4 WIB 92). On the order in which you sell lots acquired after 1 January 2026, the law says nothing: a chronological administration (FIFO) is the most defensible approach, and that is the one Cryptotax uses too. What the law equally fails to make clear is how you keep track of your lots correctly when your crypto is spread across exchanges, wallets and chains. The result: four concrete mistakes that are widely made in practice, and that can significantly distort your taxable base.
Mistake 1: Your lot history starts over after every transfer
You buy ETH on Kraken in 2022. In 2025 you move that ETH to your MetaMask. In 2026 you sell.
Anyone keeping records manually often books the arrival on MetaMask as a new purchase at the market price of that moment. Wrong. A transfer between your own wallets or exchanges is not a taxable disposal. The law is explicit about this: only a "transfer for consideration" triggers the tax. Moving your own ETH does not do that.
The original 2022 lot remains intact. Cost price, purchase date, everything. Anyone who books the arrival on MetaMask as a new purchase throws their lot administration into disarray: the actual cost price from 2022 disappears, and at the real sale an incorrect basis is used. You then pay tax on a gain you never realized.
The solution requires discipline: every transfer must be identified as such. The cost price stays linked to the lot, regardless of where that lot is moved to.
Mistake 2: Wraps and bridges are not a sale
Converting ETH to WETH. Bridging ETH from Ethereum to Base. Wrapping stETH to wstETH. In many tools these become taxable events. In our interpretation these are continuity events: you are not transferring for consideration, you are only changing the technical form or chain of the same underlying holding. (Note: there is as yet no official Belgian guidance specifically on wraps and bridges. This is the most logical tax interpretation, but not legal certainty.)
The cost price and the purchase day of the original lot keep running. A tool that books a bridge or wrap as a sale creates a fictitious capital gain that is not taxable. At the same time the original purchase price disappears from the calculation, so that at the real sale a wrong cost price is used. Wrong twice over.
Mistake 3: Staking rewards are free crypto with no tax cost price
Every staking reward you receive is, at the moment of receipt, already taxable as movable income. In most cases at 30%. That market value at the moment of receipt is precisely the tax cost price of that lot.
That has two consequences that most people overlook.
First, every reward is a separate lot. Anyone who received a hundred small ETH rewards in 2024 and 2025 has a hundred separate lots, each with its own date and cost price, which mix chronologically with the purchase lots in your administration.
Second, at the later sale of those rewards you only pay 10% on the capital gain above the already taxed value. You are not taxed twice, but you do have to keep that separation correctly. No spreadsheet does that automatically and correctly.
Mistake 4: The reference date of 31 December 2025 always protects you
Most investors understand the step-up basis as a protective mechanism: gains built up before 2026 are exempt, and the market value on 31 December 2025 becomes the new cost price. Correct, but the interaction with your lot administration creates subtleties that few people realize.
For your pre-2026 holdings the law does not work with separate lots: all the units you held on 31 December 2025 together receive an average acquisition value per asset, based on the snapshot value. If you sell part of it in 2026, you calculate with that average, not with the price of a specific lot. Depending on the price evolution after 1 January, that can produce an unexpected capital gain or loss relative to the snapshot.
There is also a lesser-known exception: anyone who held crypto on 31 December 2025 that at that moment stood lower than the original purchase price may, until 2030, use the original purchase price as the cost price. In that case the step-up is not the market value of the snapshot, but the average of the original purchase prices. Anyone who does not know this leaves a legal protection unused.
