Most savers miss this allowance

Few people know about the Additional Permitted Subscription, an extra Isa allowance for grieving spouses. It lets you deposit a deceased partner's Isa savings into your own account above the normal £20,000 yearly limit.

“There's an added benefit to putting your cash into an Isa that few savers know about.”

How the allowance works

If your partner had £50,000 in Isas, you can deposit this into an Isa in your name over and above your own £20,000-a-year limit. You need to request a certificate from each original provider showing your extra allowance.

You can switch providers

You can open a new cash Isa with the original provider or choose another, as long as they accept Additional Permitted Subscriptions. Not all providers accept them, and the information is often hard to find on their websites.

Rates can be disappointingly low

Many providers offer poor rates on Additional Permitted Subscription accounts, often half the 4 percent-plus available on standard easy-access Isas. Staying with the original provider after bereavement may be a costly mistake.

“Disappointingly, the rates for APS accounts can be awful, often half of the 4 per cent-plus you can get on an easy-access Isa account, or less.”

Building societies vary widely

Nationwide only accepts its Triple Access Isa at 3.3 percent. Skipton and Coventry offer dedicated accounts at 2.05 percent. Leeds doesn't accept the allowance at all. Yorkshire is worth considering for better rates.

Yorkshire offers better options

Yorkshire lets you pick from its easy-access and fixed-rate Isas, including an Easy Access Isa at 3.6 percent and a one-year-fixed at 4.4 percent. This gives more flexibility than many competitors.

Major banks offer poor rates

Lloyds, Halifax, Santander, HSBC, NatWest and Barclays all accept the allowance into easy-access accounts but pay low rates. Lloyds offers just 0.75 percent, while HSBC's best rate is 3 percent if you have an HSBC current account.

Fixed-rate options at banks

Barclays and NatWest offer fixed-rate Isas that accept the Additional Permitted Subscription. These may be worth exploring if you prefer locking in a rate rather than easy-access accounts.

Best rates outside traditional banks

Trading 212 offers 4.61 percent for the first year on an easy-access Isa. Virgin Money Double Take E Isa pays 4.15 percent with two withdrawals a year. National Savings & Investments Direct Isa pays 3.8 percent.

It becomes a regular Isa

Once you open an Additional Permitted Subscription account, it becomes an ordinary cash Isa. You can transfer it between providers in the usual way if you find a better rate later.

Shop around for the best deal

Don't assume the original provider is your best option. Compare rates across building societies, banks and app-based providers to maximize your tax-free savings after bereavement.