Structured Deposits and Principal-Protected Products: What International Investors Need to Know

Structured deposits occupy an unusual space in the savings and investment landscape. They offer something that sounds almost too good to be true — a savings product linked to stock market performance but with your capital returned at the end regardless of market conditions. The reality is more nuanced, and for internationally mobile HNW investors, understanding the product clearly is essential before committing capital for the typically five-to-six-year terms these products run.

What a structured deposit actually is

A structured deposit is a bank deposit — your money sits on the bank's balance sheet, just like a regular savings account. The difference is that instead of earning a fixed interest rate, the return is determined by a formula linked to an external reference, most commonly a stock market index like the FTSE 100 or the Eurostoxx 50.

The bank uses the deposit to fund its operations and simultaneously enters into options or other derivatives that create the payoff profile promised to the depositor. The mechanics are complex but the depositor's experience is simple: deposit £100,000 for five years; at maturity, receive £100,000 plus a return calculated by the index formula (or £100,000 alone if the index conditions are not met).

The principal-protected version

The most conservative structured deposit variant offers capital protection regardless of index performance:

A typical product: "deposit £100,000 for five years; receive 100% of your capital back at maturity; also receive 60% of any growth in the FTSE 100 over the five-year period."

In this case:

• If the FTSE 100 rises 40% over the period, you receive £100,000 + (40% × 60%) = £100,000 + 24% = £124,000
• If the FTSE 100 falls 30%, you receive £100,000 — your capital back, no gain
• If the FTSE 100 rises 80%, you receive £100,000 + 48% = £148,000

The "cost" of the capital protection is that you only participate in 60% (or whatever the participation rate is) of the index upside. You forgo the remaining 40% of upside to pay for the protection.

This structure has genuine appeal for savers who want some equity participation without the downside risk. However, the effective interest rate comparison should be made carefully. If bank deposits are paying 4% annually over five years (approximately 22% compounded), and the FTSE 100 returns a historical average of 7–8% per year, the participation rate determines whether the structured deposit outperforms a simple savings account.

The barrier (capital-at-risk) version

Many structured deposits — particularly those marketed as offering higher participation rates or additional returns — include a capital protection condition rather than unconditional protection:

A typical barrier product: "deposit £100,000 for five years; if the FTSE 100 never falls more than 50% below its starting level on any observation date, receive 100% of capital plus a fixed return; if the FTSE 100 falls more than 50% at any observation date, receive back only the proportion of capital corresponding to where the index finishes at maturity."

The 50% barrier sounds comfortable. But:

• During the 2008 financial crisis, the FTSE 100 fell approximately 48% from peak to trough — coming within 2% of triggering a 50% barrier
• During the COVID-19 pandemic in March 2020, the FTSE 100 fell approximately 35% in a matter of weeks
• Many products issued in 2007–2008 triggered barrier events, causing material capital losses for depositors who believed they had conditional protection

Barrier products are appropriate risk instruments for informed investors, but they are not the same as genuine capital protection products. The key risk is that barriers are designed to look very safe based on historical drawdown analysis — until the event that exceeds historical experience occurs.

FSCS protection and counterparty risk

Structured deposits issued by a UK-authorised bank are covered by FSCS deposit protection up to £120,000 per depositor per institution (raised from £85,000 on 1 December 2025). For amounts above this threshold, the depositor is an unsecured creditor of the issuing bank.

In practice, structured deposits are often issued by investment bank subsidiaries rather than retail bank entities. The relevant FSCS depositor protection limit applies per authorised firm (banking licence) — so deposits held with different brands sharing a single licence are aggregated under the one £120,000 limit. If you hold structured deposits issued by multiple entities within a banking group, check whether they share a banking licence.

For amounts substantially above £120,000, the credit quality of the issuing bank is a material factor in the risk assessment. A structured deposit issued by a G-SIB (Global Systemically Important Bank) carries lower counterparty risk than one issued by a smaller, specialist structured product issuer.

Tax treatment of structured deposit returns

The tax treatment of structured deposit returns is an area where precise advice from a UK tax adviser is important, as the rules are not entirely straightforward.

Income tax treatment: in most cases, the return from a structured deposit is treated as interest income for UK tax purposes, taxable at income tax rates (20%/40%/45%). This applies even if the return is expressed as "capital growth" in the marketing materials — the substance of the arrangement determines the tax treatment, not the marketing language.

Timing of taxation: the return may be taxable in the year it accrues, not just when the deposit matures. Where a structured deposit pays out after five years, the UK tax on the return may be due in the year of payment rather than spread over five years — this can push a basic-rate taxpayer into higher-rate territory in the maturity year. Some products allow for this by design.

Capital gains treatment: structured notes (securities, not deposits) may qualify for CGT treatment rather than income tax. The rate for CGT is 18% (basic-rate taxpayers) or 24% (higher-rate) following the increase on 30 October 2024 — generally lower than the equivalent income tax rates. Whether a particular product gives rise to income or capital gains requires analysis of the specific terms.

Offshore structured notes for HNW investors

Private banks serving internationally mobile HNW clients frequently offer structured notes rather than structured deposits:

A structured note is a security issued by an investment bank. It typically offers the same economic payoff as a structured deposit (capital protection plus index-linked upside) but is packaged as a note rather than a deposit. The note can be:

Held directly: the note sits in the client's investment account. Returns are subject to income tax or CGT depending on the structure. FSCS investor protection (up to £85,000) applies if the issuing firm fails.

Held within an offshore bond wrapper: an offshore bond (typically structured as a Isle of Man or Guernsey life assurance policy) can hold structured notes. Inside the wrapper, the return accrues free of UK income tax and CGT. Tax is only triggered on "chargeable events" — partial surrenders above the 5% per annum tax-deferred withdrawal allowance, or full surrender. For higher-rate taxpayers, deferral until a lower-income period (retirement, return to a lower-tax jurisdiction) can significantly improve the net return.

The offshore bond approach adds insurance company charges (typically 0.5–1% per year of wrapper cost) but defers the tax liability. Whether the deferral benefit outweighs the wrapper cost depends on your marginal tax rate, the investment horizon, and when you expect to surrender.

Comparing structured deposits against alternatives

Before committing to a structured deposit, compare against:

Fixed-rate savings: if market rates are attractive, a simple fixed-rate deposit from a well-capitalised bank may outperform a structured deposit's expected return without the complexity and illiquidity.

Diversified equity investment: historically, FTSE 100 total return (including dividends) significantly outperforms the participation rate on a structured deposit. An investor comfortable with short-term volatility may prefer direct equity exposure.

Premium Bonds (NS&I): for capital preservation with some upside potential, Premium Bonds backed by HM Treasury carry zero credit risk. The prize rate is variable but the capital is unconditionally protected — unlike barrier structured deposits.

Investment bonds (onshore or offshore): for the tax deferral feature, comparison against the offshore bond wrapped around a straightforward equity fund is appropriate.

How Global Investments can help

Global Investments works with internationally mobile HNW clients on the investment and savings component of their financial strategy. Our team includes specialists familiar with the full range of structured products, offshore bond wrappers, and the tax planning that sits alongside them.

We can help you assess whether a structured deposit or note presented to you by a bank is genuinely suitable for your tax position, liquidity requirements, and risk tolerance. We can also access structured products through independent channels, rather than solely through your existing bank relationships, ensuring you see the full market.

This guide reflects our understanding as of June 2026. Tax rules, FSCS limits, and product availability change. Always take specific advice from a qualified financial adviser before investing in structured deposits or structured products. Past performance of underlying indices does not guarantee future results.