Capital Gains Tax & FIFO: Is anyone planning to use ISIN-rotation (e.g., IWDA -> SWRD -> WEBN) to control realization?
Hi all,
First of all, amazing subreddit and learned a lot already, thanks for that!
So...
With the 10% capital gains tax and the strict application of the FIFO principle per financial asset, I’ve been thinking about the long-term mechanics of decumulation.
If you DCA into a single ETF (like IWDA) for 20–30 years, FIFO dictates that every sale forces you to dispose of your oldest shares first—the ones with the largest accumulated gains. While using multiple brokers might work locally at the broker level, the tax authority legally looks at you as a taxpayer per ISIN, meaning multi-broker setups for the exact same fund might not be tax-tight if audited centrally.
EDIT: as pointed out in the comments, you can use different brokers also (in Belgium).
I'm considering ISIN rotation (the "tranche strategy"):
Phase 1 (Years 1–7): Accumulate ETF A (e.g., IWDA)
Phase 2 (Years 8–15): Switch to ETF B (e.g., SWRD)
Phase 3 (Years 16+): Switch to ETF C (e.g., WEBN)
Why this matters when selling:
Having separate ISINs gives you full control over your tax bill depending on your goal.
Big lump sum needed? Sell your newest ISIN. Low profit per share keeps you under the €10k tax-free limit (€0 tax).
Annual FIRE income needed? Sell your oldest ISIN. High profit per share lets you extract maximum tax-free cash up to €10k (or €15K/€30K).
Is anyone else here planning to implement this?
Do you see any major downsides (e.g., tracking differences, liquidity, slightly higher TERs on alternatives)?
Curious to hear your thoughts and strategies!
Note: I used AI to help structure, format, and polish the English phrasing for this post.