Helping Mum plan to reduce exposure to Tax on Savings Interest - thoughts invited

panam

Have you investigated offset mortgages? These link a savings account with the mortgage account, and you only pay interest on the difference. They tend to be more expensive, but a fully offset  mortgage would cost nothing in interest.
Usually this is your own savings, but some providers allow the savings account to be held by a relative (check YBS). So it would remain as your Mum's money, under her control, but with no taxable interest.
You would be making smaller mortgage repayments (capital only) and as the amount owing reduced, your Mum could draw down on the savings pot (keeping the 100% offset).
Effectively she is making a gift of the sacrificed interest to you.