One rate change. Three different effects.

Follow a fictional household and small business to see how interest rates connect to spending, cash flow and business value. All figures are illustrative, not forecasts.

1. A household with floating-rate debt

Imagine £200,000 of interest-only borrowing. A rate increase from 4% to 5% adds £2,000 a year, or about £167 a month, if it passes through immediately and in full. This is an interest-only illustration, not an amortising mortgage quote. A fixed-rate borrower may not feel the change until their deal ends.

Try it: use the mortgage comparison tool for repayment borrowing. Compare the same balance and term. Include fees and the remaining balance when comparing real offers.

2. A profitable business waiting to be paid

A fictional business starts with £12,000 cash. It invoices a customer £20,000 but must pay £8,000 of costs this week. Until the customer pays, it has only £4,000 cash. Profit and available cash answer different questions.

If the customer pays a month late, the business may need temporary funding. At 8% annual simple interest, borrowing £10,000 for 30 days costs approximately £66 (£10,000 × 8% × 30/365), before fees. A stronger headline margin does not remove the timing problem.

Try it: read the 13-week cash forecast guide. Separate the invoice date from the cash receipt date and shift the receipt to stress-test headroom.

3. The valuation of future cash

Suppose a business is expected to generate £10,000 in five years. Its present value is about £6,806 at an 8% discount rate and £6,209 at 10%. The expected cash is unchanged; a higher required return makes distant cash worth less today.

This single cash flow is not a full business valuation. A real DCF also needs operating forecasts, reinvestment, working capital, terminal value and a debt/cash bridge. A central-bank rate change does not translate one-for-one into every business discount rate.

Try it: open the valuation lab. Change one assumption at a time and explain what causes the movement before trusting the chart.

Where oil and inflation fit

Higher oil costs can raise transport and production costs, reducing household spending power and business margins. But an oil-price rise driven by strong demand can accompany growth; a supply disruption can weaken activity. Contracts, exchange rates and policy responses change the result. Avoid treating one headline as an automatic investment signal.

Check your understanding

A company reports a profit. Can it still run out of cash?

Yes. Customers may pay after wages, suppliers and tax fall due. Compare receipt/payment dates, not just the profit margin.

Does every mortgage payment increase immediately after a rate rise?

No. Fixed-rate contracts, lender pricing and reset dates matter. Even floating-rate products do not all follow the same reference rate.

What is £10,000 received in five years worth at a 10% discount rate?

£10,000 ÷ 1.10⁵ = approximately £6,209. This is an illustration, not an investment recommendation.

Your next step

Choose the question you need to answer: household budget, profit versus cash, or business valuation. Guided learning packs build on these free foundations; availability is shown on each product page.