This calculator is for illustrative purposes only. The projections shown do not represent a guarantee of future returns. As with any long-term projection, changes in the underlying assumptions — including tax rates, investment returns, inflation, and individual circumstances — may significantly affect the actual outcome. This tool should not be relied upon as financial advice.

How the Calculations Work

• The calculator applies fixed annual return assumptions based on Tideway's investment portfolios. These are not guaranteed and actual returns will vary.
• Returns are split between anticipated long-term average capital gains, dividend income, and bond interest. Each component is treated differently for tax purposes.
• In the taxed account (GIA) projection, income and gains are taxed each year at the rates entered in the assumptions. As a result, withdrawals from the account are taken from already-taxed capital and are not subject to further tax.
• Within the offshore bond, investment returns accumulate without annual UK tax deductions, allowing the full return to compound over time.
• Withdrawals from the offshore bond are treated as tax-free to the extent that cumulative withdrawals do not exceed the total 5% annual allowances accrued — effectively until the original capital invested has been returned in full.
• Once the 5% cumulative allowance is exhausted, further withdrawals are subject to income tax on the chargeable gain element. In this calculator, withdrawals are grossed up by the income tax rate assumption so that the investor continues to receive the same net amount.

What the Calculations Show

• Over shorter time horizons — typically under 20 years — the benefit of using an offshore bond wrapper may be limited, particularly if the investor intends to fully withdraw funds during that period.
• Offshore bonds defer tax rather than eliminate it. All gains within the bond are ultimately assessed as income on encashment. Where an investor's portfolio generates significant capital gains, the final tax liability on withdrawal from a bond may exceed that which would have been paid annually in a directly held, taxed account — since capital gains tax rates are lower than income tax rates.
• The potential advantage of an offshore bond is most apparent when the bond is held for more than 20 years and withdrawals are taken at a rate that allows the investment to maintain or grow its real value. In this scenario, the ongoing deferral of tax supports the preservation of the capital base.
• Offshore bonds structured as capital redemption bonds can have a maximum term of up to 99 years and may be passed between generations. Under current rules, a gift of a bond or segment that is survived by seven years may fall outside the donor's estate for inheritance tax purposes. Tax rules may change, and individual circumstances will vary.
• Offshore bonds may offer tax efficiency where they are encashed outside the UK in a lower-tax jurisdiction, or where they are assigned to a nil-rate or lower-rate taxpayer. Under top-slicing rules, the tax due on encashment may be reduced or eliminated for lower-income recipients, including minors. Professional advice should be sought before relying on these outcomes.
• Within the bond, switching between investment funds does not trigger an immediate tax charge. By contrast, an investor holding funds directly who realises a capital gain will incur a CGT liability on disposal, which reduces the amount available for reinvestment. This structural difference can improve long-term outcomes when active portfolio management is required.

Key Terms Explained

Top Slicing Relief

Where a chargeable gain arises on the full or partial encashment of an offshore bond, top slicing relief may reduce the rate of income tax payable. The total gain is divided by the number of complete years the bond has been held, and this "top slice" is added to the individual's other income to determine the applicable tax rate. That rate is then applied to the whole gain. For example, a £200,000 gain on a bond held for 20 years would produce a top slice of £10,000. If encashed by an individual with no other income whose total income (including the top slice) falls within the personal allowance, no income tax may be due on the gain. Tax treatment depends on individual circumstances and may be subject to change.

Tax-Efficient Fund Switching

Investors holding funds directly in a general investment account who wish to switch between funds must sell their existing holdings and may incur a capital gains tax liability on any accumulated gain before reinvesting the proceeds. This reduces the capital available to reinvest. Within an offshore bond, fund switches can be made without triggering an immediate tax charge, meaning the full value of the investment can be redirected. Over time, this structural advantage can contribute meaningfully to overall investment returns, though the benefit will depend on the frequency of switches and the size of gains involved.

For more information, please speak to a Tideway adviser or visit our offshore bonds page.