Tax-loss harvesting is much harder to write a single, universally correct guide for in Europe than in the US, precisely because there is no European equivalent to the wash-sale rule — capital gains and loss offset rules are set nationally, and they differ substantially from country to country. This guide covers the general screening logic that applies across most jurisdictions, and is explicit about where it stops and a local tax professional's advice needs to start.
This is informational content, not tax advice. Capital gains tax rules, loss offset rules, and reporting requirements vary significantly by country of tax residence and can change from year to year. Consult a qualified tax professional in your country of residence before making any decisions based on this guide.
Last updated: July 2026.
The general logic behind tax-loss harvesting
The core idea is consistent across most tax systems that tax capital gains: realising a loss on a position that has declined in value can offset realised gains elsewhere in a portfolio (and in many jurisdictions, can be carried forward to offset future gains), reducing the investor's overall tax liability for the year — without necessarily changing the long-term portfolio strategy, if the position is later re-established or replaced with something similar.
Why year-end specifically: Most tax systems assess capital gains and losses on a calendar- or fiscal-year basis, making the final weeks of the tax year the natural — though not the only sensible — time to review a portfolio specifically for harvesting opportunities, alongside realised gains earlier in the year that a loss could offset.
Why this varies so much more in Europe than in the US
No pan-European wash-sale equivalent. In the US, the wash-sale rule disallows a loss deduction if a "substantially identical" security is repurchased within 30 days before or after the sale. European countries have their own, often quite different, rules — some have similar anti-abuse provisions, some have different holding period requirements, and some have simpler or more permissive treatment.
Capital gains tax regimes themselves differ substantially. Some European countries tax capital gains as ordinary income, some apply a flat rate, some offer exemptions after a minimum holding period, and some have different treatment for gains inside versus outside tax-advantaged account wrappers. A strategy that makes sense under one country's regime can be irrelevant or even counterproductive under another's.
Loss carryforward rules vary. Whether — and for how long — a realised loss can be carried forward to offset gains in future years differs by jurisdiction, which affects how much urgency there genuinely is to realise a loss before year-end versus simply holding the position.
Given this variation, the responsible approach for this guide is to describe the general screening logic — which positions are candidates for review — while being explicit that the actual decision of whether, when, and how to realise a loss depends entirely on rules specific to your country of tax residence.
A general screening checklist for candidates
None of the following steps constitute tax advice — they identify candidates worth discussing with a tax professional, not a final action list.
1. Screen your portfolio for unrealised losses
The starting point is simple: which current holdings are trading below your cost basis. Most portfolio tracking tools, including the position tracking available in ScreenerHero, show unrealised gain/loss directly.
2. Distinguish a temporary setback from a permanently impaired thesis
A tax-loss harvesting candidate you still believe in — one you intend to hold long-term but which happens to be down for the year — is a different situation from a position whose original investment thesis has genuinely broken down. For the latter, review whether it's also a value trap worth exiting entirely rather than one to simply harvest and re-establish.
3. If you intend to maintain market exposure, understand your jurisdiction's rules before replacing the position
Some investors sell a losing position and immediately buy something similar to maintain market exposure while realising the tax loss. Whether this is permitted, and under what conditions (holding period, "substantially identical" definitions), depends entirely on your country's specific rules — this is exactly the point where local tax advice is not optional.
4. Check whether you have realised gains earlier in the tax year to offset
Tax-loss harvesting is most valuable when there are realised gains elsewhere in the portfolio (or in some jurisdictions, carried-forward gains) that a new loss can directly offset. Review your realised gain/loss position for the year before deciding how much loss-harvesting activity is actually useful.
5. Confirm your specific jurisdiction's deadline and reporting requirements
The "December 31st" year-end assumption doesn't hold universally — some jurisdictions use a different fiscal year, and settlement timing (when a trade must complete, not just be initiated, to count within a given tax year) varies by market and broker. Confirm both with your broker and, ideally, a tax professional before assuming a trade placed near year-end will settle within the tax year you intend.