Flagstone Cash ISA Quadruples in Size With Launch of Fixed-Term Accounts

  • Infrastructure
  • 12.05.2026 11:17 am

 Flagstone, the UK's largest savings platform* managing over £19 billion of UK savers' cash, has announced the next phase of its Cash ISA rollout, adding fourteen fixed-rate accounts to its flexible Cash ISA wrapper and doubling the number of ISA providers on its banking panel to ten. 

In February, Flagstone launched the Flagstone Cash ISA - a single tax-wrapper within which a saver could open and maintain up to five tax-free instant access accounts in one ISA wrapper. This expansion into fixed term deposits is the second phase of Flagstone's planned Cash ISA rollout. From today, savers can open and maintain 8 instant access and 14 fixed term accounts all within one single tax wrapper.

The Flagstone Cash ISA offers a hassle-free, tax-free savings experience to savers fed up with the time and admin they have to put into keeping track of multiple Cash ISAs, and removes many of the limitations that have become standard in Cash ISA small-print. Within the flexible Flagstone Cash ISA, savers can arrange straight-through transfers into their Cash ISA account, and withdraw and add cash within the Flagstone tax wrapper within moments, as many times as they wish, without penalties and without affecting their annual tax-free allowance. Savers manage everything through a single Flagstone dashboard, with full visibility of both their ISA and non-ISA holdings in one place.

Flagstone's new fixed term ISAs offer savers rates of up to 4.45% on terms of between three months and two years. Fixed rate accounts give savers certainty over returns over defined periods of time and can be a great way to maximise available rates while maintaining some liquidity when combined with instant access accounts.

The fixed term ISAs are offered by existing Flagstone ISA providers Oaknorth and Kroo and new Flagstone ISA partners Santander International, Al Rayan Bank and IS Bank. These banks join existing instant access ISA providers Griffin, LHV, Paragon, RateSetter and Arbuthnot Direct within the Flagstone wrapper.

Bigger panel, greater protection

Doubling the number of banking partners within the ISA wrapper has a significant, direct impact on the FSCS protection available to Flagstone Cash ISA savers. With ten banks now offering accounts within the Cash ISA wrapper, individual savers can FSCS protect £1.2 million in tax-free savings in one place.

John Martin, Chief Product Officer at Flagstone, said: "Early take up by both existing and new Flagstone customers has been very encouraging, and it has only reinforced our conviction that ISA savers want simplicity, flexibility and choice - all in one place. 

As market volatility continues and tax policy changes gear up to take effect, the way that Flagstone customers are behaving suggests that savers are allocating more of their financial portfolio to cash to manage risk and ensure value preservation and liquidity. That makes it more important than ever to ensure they have access to the best possible rates, tax-free returns and the strongest protections available. 

Doubling our banking panel from five to ten within three months of launch reflects the appetite we’re seeing from both savers and banks to maximise their Cash ISA opportunity. Even in a changing ISA market, we’re focused on providing high-performing, protected savings products for customers who value certainty, access and return.”

Tom Robinson, Product Director of Personal Savings at Oaknorth added:”The importance of maximising the security of your cash with adequate FSCS protection has never been greater. However, for savers with larger balances, spreading deposits across multiple accounts to stay within protection limits can create a significant administrative burden. Being part of Flagstone’s ISA panel at launch helps simplify that process, allowing customers to manage their savings more easily in one place, while still benefiting from strong protection and competitive rates.”

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