XTB hasstarted letting Polish clients decide exactly which shares or ETFs they sell,instead of pushing every disposal through the first-in, first-out method, orFIFO, that has long governed how the country's brokers calculate taxable gains.The featurewent live on May 29, and the company says it is the first brokerage in Polandto offer it.The pitchis tax. By choosing the lot they sell, investors get a say in the size of thegain they realize, and therefore the bill they hand to the tax office.How FIFO Inflates the TaxBillPolandtaxes capital gains at a flat 19%, the levy known locally as “the Belka tax,” afterMarek Belka, the finance minister who introduced it in 2002. When an investorbuys the same stock in several tranches at different prices and later sellspart of the holding, the cost basis assigned to that sale decides how large thetaxable gain is.Under FIFO,the earliest purchases are treated as sold first. On a position that hasclimbed over time, those are usually the cheapest shares, which maximizes therecorded gain and the tax due.XTB, like other domestic brokers, had beenapplying the rule automatically.Polish lawdoes let investors identify the actual purchase price of the shares they sell,so FIFO is a default rather than the only path. Brokers have stuck with itpartly because exchange-listed shares are dematerialized, which makes it hardto pin down which specific shares left an account. XTB nowlets clients make that call themselves, or keep FIFO if they prefer.Routine Abroad, New forWarsawChoosingtax lots is standard fare in more developed brokerage markets. InteractiveBrokers has long run a tool it calls the Tax Optimizer, which lets clientsoverride FIFO with last-in first-out, highest-cost, or manually selected lotsacross its desktop, mobile, and web platforms. In theUnited States, the IRS permits this so-called specific identification as longas the investor flags the chosen lot at the time of sale.Automatedversions have been around for years too. The robo-advisers Betterment andWealthfront built tax-loss harvesting, which sells losing lots to offset gainselsewhere, into their platforms more than a decade ago, with Bettermentlaunching its tool in 2014.However, notevery market allows the move. Germany makes FIFO mandatory for securities underits flat withholding tax, leaving investors no room to pick lots, while theUnited Kingdom pools shares of the same class together and applies a 30-daymatching rule meant to stop investors gaming disposals. Poland'sFIFO default has sat closer to the German model, which is what makes XTB'schange notable at home even as it catches up to tools traders elsewhere takefor granted. XTB'sversion is also narrower than Interactive Brokers' menu, offering a choicebetween manual selection and FIFO rather than a suite of algorithms, and itworks only inside an XTB account. The brokerhas spent the past year extending its options product acrossEurope and addingspot crypto, so a tax feature fits a wider effort to broaden what the platformdoes.What It Changes forInvestorsFor activeinvestors, the tool has real bite. Someone sitting on gains can close ahigher-cost lot to book a loss that offsets earlier profits, or hang on to thecheapest shares to push that tax into a later year. For a buy-and-hold saverwho rarely trims positions, it changes little.OmarArnaout, XTB's chief executive, tied the launch to client demand."Investors have been asking us about the ability to manage individualpositions for a long time," he said, adding that the company moved ahead"after external tax consultations" confirmed the approach wasworkable. He alsodescribed XTB as "setting standards for the entire sector," a framingthe company applied to its own product.XTB pairedthe announcement with a claim that morethan one in three investors in Poland now holds an account with it, whichis confirmed by the latest KDPW data.XTB hasbeen drawing new traders onto theplatform at pace,counting more than 2.16 million clients globally at the end of 2025. The taxfeature also has limits worth noting: it optimizes only within a single XTBaccount, since each broker issues its own annual tax statement, and FIFO staysin place as the fallback.A Product Push Backed byHeavy MarketingXTB rolledout the change during an unusually strong stretch of results. The Warsaw-listedbroker reported first-quarter net profit ofPLN 535 million, up176% from a year earlier, on operating income of PLN 1.09 billion.That growthhas been bought, in part, with marketing. XTB lifted its marketing spend by closeto 70% in 2025 toPLN 584.9 million and added 864,000 accounts during the year, a 73% jump. Ithas also kept regulators busy at home, absorbing a record fine fromPoland's KNF thatinvestors largely shrugged off.The widerpoint is that all the maneuvering around FIFO stems from how Poland's capitalgains levy was built. The tax arrived as a temporary measure more than twodecades ago and has outlasted repeated talk of reform. Until thefinance ministry reworks it, brokers competing for Polish savers are left toengineer their own workarounds, and XTB has now turned one of them into aselling point.This article was written by Damian Chmiel at www.financemagnates.com.