What is a sinking fund and how do I build one?

Full answer

Sinking funds are a simple but effective budgeting technique for smoothing out large, predictable expenses that would otherwise create a sudden strain on your monthly finances. **How a sinking fund works** Instead of being caught out by a large annual bill or expense, you calculate the total cost, divide it by the number of months until you need it, and set that smaller amount aside automatically each month into a separate savings pot -- so that when the expense arrives, the money is already there. **Sinking fund versus emergency fund** An emergency fund covers genuinely unpredictable events -- job loss, a boiler breakdown, an unexpected medical cost -- and its purpose is to absorb shocks you cannot plan for. A sinking fund, by contrast, covers expenses you know are coming, even if you do not know the exact date or amount in advance -- car servicing, an annual holiday, Christmas, home maintenance, or an insurance renewal are common examples. Keeping the two separate helps ensure your emergency fund is not depleted by predictable spending that should have been planned for. **Common sinking fund categories** Many households find it useful to run multiple small sinking funds for different purposes -- for example a car maintenance and replacement fund, a home repairs fund, an annual holiday fund, a Christmas and gifts fund, and a fund for annual subscriptions or insurance renewals paid in a single lump sum. **How to calculate the monthly contribution** Estimate the total cost of the expense and the number of months until it is due, then divide the total by the number of months. For example, if you expect to need £1,200 for car maintenance and a new set of tyres over the next 12 months, you would set aside £100 per month. **Where to keep sinking fund money** Many people use a separate easy-access savings account (sometimes with sub-pots or "buckets" offered by some banking apps) specifically for sinking funds, keeping the money separate from everyday spending and easily identifiable for its intended purpose, while still earning some savings interest. **Worked example** Someone knows their car insurance renewal (£600) and annual boiler service (£150) are both due next year. They set up a single sinking fund and contribute £62.50 per month (£750 divided by 12), so both bills are fully funded without disrupting their regular monthly budget when they arrive. **Practical tip** Use the Budget Planner calculator to identify your recurring annual and occasional expenses, then build a monthly sinking fund contribution into your regular budget so these costs never come as a surprise.

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