Tools we think are worth knowing about for UK tax planning, investing, and managing your finances. All recommendations are based on relevance to the calculators and guides on this site.
A Self-Invested Personal Pension (SIPP) is the most tax-efficient savings wrapper available to UK taxpayers. Contributions attract Income Tax relief at your marginal rate — 20%, 40%, or 45%. For anyone in the £100k–£125,140 taper zone, SIPP contributions can effectively cost as little as 40p per £1 invested once the Personal Allowance restoration is factored in.
Related: PAYE calculator · How pension contributions reduce tax · £100k trap guide
Good bookkeeping software makes Self Assessment significantly less painful — tracking income, expenses, mileage, and invoices throughout the year rather than reconstructing everything in January. MTD for Income Tax (Making Tax Digital) becomes mandatory for self-employed people with income above £20,000 from April 2026.
Related: Self-employed take-home calculator
Tracking dividends across ISA and non-ISA holdings is essential for accurate self-assessment returns and avoiding unexpected tax bills. The £500 dividend allowance means even modest portfolios outside an ISA can trigger a filing requirement.
Related: Dividend tax calculator · Dividend tax guide
Running payroll, filing accounts with Companies House, and optimising salary vs dividend extraction requires either a good accountant or strong software — ideally both. At director income levels above £50k, accountancy fees typically pay for themselves many times over in tax savings alone.
Related: Salary vs dividend calculator · Corporation tax calculator
A whole-of-market mortgage broker has access to deals not available directly to consumers and can model overpayment flexibility, offset options, and fixed vs variable scenarios. For anyone considering overpayments, understanding your mortgage's overpayment limit (usually 10% per year without penalty) is essential before committing funds.
Related: Mortgage overpayment calculator · Overpay vs invest guide
The £20,000 annual ISA allowance is the most widely available tax shelter in the UK — sheltering returns from both income tax and CGT. At higher income levels (40%+), the compounding effect of sheltered growth is substantial over a decade. S&S ISAs are particularly efficient for long-term investors who would otherwise pay CGT on gains.
Related: Capital gains tax calculator · Overpay mortgage vs invest
Affiliate disclosure: some links on this page may be affiliate links. If you use one, we may receive a small commission at no extra cost to you. This does not influence which products are listed or how they are described. Sterling Calculators is not a financial adviser — these are informational recommendations only. Always do your own research before making financial decisions.