Opening up Cash ISAs: Introducing an enhanced savings platform

The Flagstone savings platform has supported investors to grow some £18bn of assets over the years. Advisers have been an essential part of that story, recommending Flagstone to their clients to build scalable cash portfolios. But there’s so much more to come. 

In 2026, we’re adding Cash ISAs to our savings platform to complement our wide range of high interest accounts. Designed for ease of use, the new launch takes aim at the unwieldy processes that are limiting the growth potential of your clients’ cash. 

Here’s how your clients will benefit from the new Cash ISA, delivered by Flagstone. 

Common Cash ISA challenges

Cash ISAs have always played an important role in effective money management. In fact, subscriptions rose by 67% over the 2023/24 tax year, according to figures published by HMRC.  

But despite their usefulness for limiting tax burdens on savings, the customer experience remains awkward. It has failed to scale with the savings individuals have grown. 

Inconsistent ISA rules limiting clients’ ambition

Take switching, for example. A 2025 survey conducted by Flagstone of 180 advisers found that 95% of savers wanted to take advantage of higher interest rates. But transferring Cash ISAs isn’t always easy.  

Different providers often follow their own procedures. Clients may also believe they can withdraw their money and pay it into a new ISA without any consequences. But if funds are not transferred using the correct ISA transfer process, they risk the tax-free status of their cash, compromising interest earnings, or reducing annual allowances. 

If your clients have built up multiple Cash ISAs over years, those accounts may be sitting across a handful of different banks. This creates gaps in visibility, making it tough to track interest rates or maturity dates across a secure portfolio.  

Any one of these issues would cause clients to think twice before switching to maximise interest.  

Taken together, they can significantly limit Cash ISA earnings for high-opportunity clients. 

Higher interest rates await

Interest rates may have dropped from the highs of 5.25% in summer 2023. But they remain much higher than the lows of 0.1% seen as recently as 2020. As of December 2025, the interest rate was 3.75%. Despite significant earning potential, clients often stick with the account they know.  

The perfect time to switch

Cash ISAs have also been the subject of recent interest from the Chancellor. Currently, clients can save up to £20,000 tax-free. But that figure is set to reduce in the 2027 tax year for most savers. This means clients have a limited period to make use of the current level of tax-free protection on cash deposits. 

In what former Flagstone CEO Simon Merchant described as ‘a blow to savers’, the Cash ISA allowance will reduce down to £12,000 on 06 April 2027 for savers under the age of 65.  

And there are other strong reasons pushing clients to switch. Over half of the savers Flagstone surveyed (55%) wanted to consolidate multiple separate accounts into one. 34% wanted to manage their ISAs on one easy-to-use platform.  

Cash ISAs unlocked via Flagstone’s platform

Currently, the Flagstone savings platform gives advisers and their clients access to hundreds of savings accounts from multiple banks. Savers spread their cash across instant access, notice and fixed-rate accounts, maximising interest without compromising access.  

The Cash ISA continues this legacy, expanding control and simplicity for your clients’ tax-free savings. Clients use a single login to view Cash ISA products from multiple providers, set alongside their other accounts on the savings platform.  

No separate onboarding.  

No repeated forms.  

All Flagstone needs to unlock this for existing customers is a National Insurance number. 

That’s it. 

Seamless transferring

Transfer-in is one of the best ways to fund the new Flagstone Cash ISA (£10,000 minimum deposit). In our survey, 64% of advisers saw it as a core growth strategy for existing and prospective clients.  

Our platform exclusively features HMRC-approved financial partners, and is maintained by our listed ISA manager WealthKernel.  

WealthKernel is regulated by the FCS and handles account setup, custody of your ISA, and regulatory reporting. Your clients' money is held with FSCS-eligible UK banking groups. Any switches that occur within the Cash ISA automatically follow the correct transfer process, preventing mistakes, protecting allowances, and preserving clients’ tax-free status.  

It also helps your clients confidently consolidate their older ISAs, without penalties. 

And you can track every transfer through your own read-only account for the complete picture of your clients’ wealth. The Flagstone platform alerts you to new products, updated rates, and highlights maturing accounts for you to help you plan meaningful financial conversations. 

Stronger FSCS protection 

The Financial Services Compensation Scheme (FSCS) protection limit increased to £120,000 for individual accounts in December 2025. And that doubles to £240,000 for joint accounts. 

Flagstone lets clients spread their money across as many of our accounts as they want. Clients get full FSCS protection for every eligible account they open. The potential to protect every penny of their savings is just a transfer away.  

The best time to change

Demand for Cash ISAs continues to grow, driven by higher interest rates and an increased focus on cash performance. There’s also ongoing speculation around future tax-free allowances, which could reduce future returns. 

For surveyed advisers, having access to a range of products was one of the main factors in choosing a savings platform, alongside accessing high interest rates.  

Flagstone’s enhanced savings platform will open a new pipeline of untapped savings opportunities. It’ll also unlock untapped Cash ISA clients, searching for the same seamless experience that makes us the UK's highest-rated savings platform. 

With the new year finally here, there’s never been a better time to talk to clients about Cash ISAs and the benefits of switching accounts. 

Get in touch with us

For more about our 2026 launch or how we can help you maximise your clients’ savings, contact BusinessDevelopment@FlagstoneIM.com.