One-stop shop for a large cash holding under LPA

[TedSwippet]

I have just started managing my mother's money under LPA. After an inheritance, her finances have become too unwieldy to manage in the way she has up to now; too few banks for FSCS cover, and poor interest rates from those on top. She holds a simple mix of ordinary savings accounts and cash ISAs.

I'd like to see if I can move her cash to something that is fully protected, convenient for LPA management (opening new bank accounts under LPA is mostly awkward, slow and paper-based, so a single 'hub' account is attractive), and with half-decent interest rates. She is over 90, so readily accessible cash is more important than long-term return.

So far I've found only these options, but none covers the requirements:

• NS&I - Fully protected, so no FSCS issues. But interest rates are nearly always poor.
• HL Active Savings - Multiple accounts permit FSCS cover, decent rates. Offers cash ISAs, but does not support cash ISA transfer in.
• Raisin - As above on multiple accounts. But no cash ISA option at all.
• AJ Bell Cash Savings Hub - Ditto.
• Flagstone - Ditto (I think; hard to work through their web site).
• Aviva Save - Ditto.

Have I missed any other possibilities? In particular, anything that offers the full range of both savings and cash ISA options?

Failing this, any other ideas? A stocks and shares ISA holding just a single money market fund or ETF might perhaps stand in for the lack of usable cash ISA options in HL and AJ Bell, but it seems like a rather indirect (and fee-heavy) way around what are arguably platform limitations, rather than an investing or saving decision.

[Alaric]

Failing this, any other ideas? .

Direct holdings of short term Gilts? Subject to market value fluctuations until maturity but otherwise guaranteed.

Cash ISAs can now be transferred into Stocks and Shares ISAs which would enable money market OEICs and ETFs to be held.