XTB istaking another step away from its roots as a derivatives broker, rolling out aCash ISA in the UK that puts it in direct competition with savings-focusedfintech platforms like Trading 212, Plum, and recently also eToro.ThePolish-listed broker (WSE: XTB)launched the product this week, pairing it with a 6% AER introductory rate fornew customers who open an account before the end of April. The boosted rate, whichincludes a 2 percentage point bonus on top of XTB's standard 4% variable rate, lasts90 days and applies to balances up to £40,000 across eligible accounts,including both the Cash ISA and the company's existing Stocks & Shares ISA.XTB Is Completing the ISASuiteXTB entered the UKISA market in December 2024 with a Stocks & Shares ISA, but the addition of a Cash ISA isa meaningful step. It's the product that most UK savers actually use. The CashISA allows deposits of up to £20,000 per tax year, with interest earnedtax-free. XTB is structuring it as a flexible ISA, meaning customers canwithdraw and replace funds within the same tax year without losing their annualallowance.There areno account fees, no minimum deposit beyond £10, and client money is held insegregated Tier 1 bank accounts under CASS rules with FSCS protection up to£120,000.JoshuaRaymond, XTB's UK Managing Director, framed the launch around a timingargument: with markets pricing in potential Bank of England rate cuts as soonas this month, the window for locking in higher savings rates may be closing."Toomuch of the UK's savings are still parked in accounts doing very little, andmore people are now being drawn into paying tax on their interest,"Raymond said. "But with markets increasingly expecting interest rates todrop again, potentially this month, people are also realising that today'shigher returns may not last forever."Competing on Rate in aCrowded MarketXTB's 6%headline rate tops the current field, at least on paper. Trading 212 isoffering 4.4% for new customers through a 12-month bonus, while Plum'spromotional rate hits 4.32% but only for the first year. Moneybox pays 4.32%but drops sharply to 0.75% if customers make more than three withdrawalsannually. eToro,which recently entered the Cash ISA space through a partnership with Moneyfarm,offersa standard introductory rate of 3.67% AER.Thecomparison matters because XTB's 6% reverts to 4% after just 90 days - not 12months. That makes the headline figure competitive for the short term, butcustomers staying beyond the promotional window would likely find better fixedrates elsewhere.Brokers Are Divided onCash ISAsXTB'slaunch drops into a live industry debate. IG has beenpushing back against Cash ISAs through its "Save Our Stock Market"campaign, arguingthat tax-advantaged cash savings pull money away from UK equities and weakendomestic capital markets. IG has gone as far as calling for new Cash ISAopenings to be restricted.XTB isclearly on the other side of that argument. Raymond's pitch is that saving andinvesting don't have to be separate decisions, and that combining both productsin one app removes friction for customers managing their finances.Thatpositioning fits a broader pattern for XTB. The companyhas been steadily building out tax-advantaged investment accounts across Europe, launching IKZE retirement accountsin Poland last July, and PEA investmentaccounts in France in April 2025, as part of a deliberate shift toward longer-term retail investors andaway from a pure CFD trading identity.UK Retail Investing RaceIntensifiesThe UKretail investment market is getting more competitive on multiple fronts. Robinhoodlaunched a Stocks & Shares product in the UK in February, adding another well-funded name tothe mix. Meanwhile, researchsuggests one in five UK adults plans to start investing small amounts monthlyin 2026, creating alarger addressable market for platforms that can convert savers into investors.For XTB,the Cash ISA is less about dominating the savings market and more about owninga fuller slice of a customer's financial life, keeping money inside theplatform rather than losing it to a standalone savings app.Whether the90-day rate is enough to make that happen is another question.This article was written by Damian Chmiel at www.financemagnates.com.