Why a headline yield can flatter an investment

Ask ten landlords what makes a good buy-to-let and most will say "yield". It is a useful shorthand, but on its own it can be badly misleading. A property advertised at 8% gross in a quiet town with three months of empty weeks each year can leave you worse off than a 5.5% flat in a city where tenants queue up and stay for years.

Yield is simply annual rent divided by purchase price, expressed as a percentage. It tells you nothing about mortgage costs, maintenance, letting agent fees, insurance, or how often the place sits empty. Treat it as a starting point for comparison, not a verdict. The real question is what an investment returns after everything else has been paid, averaged over a decade rather than a single good year.

Where rents stretch further than prices

The gap between the cheapest and most expensive regions is striking. In much of the North East, parts of the North West, South Yorkshire, the West Midlands and South Wales, it is still possible to buy a two or three-bedroom terrace for somewhere between £90,000 and £160,000. Rents for that kind of home commonly sit between £650 and £950 a month. Run the numbers and gross yields of 6% to 8% are realistic.

That arithmetic works because rents are driven by local wages and housing benefit rates, which do not fall as far as prices do. A town with modest house prices but a steady supply of working tenants and a large rental sector can produce strong income returns year after year.

The trade-off is capital growth. In areas where prices are low relative to rents, values often rise slowly. You may collect solid income but see little increase in the underlying asset. If your plan depends on selling at a large profit in ten years, that matters a great deal.

The pull of London and the South East

Head south and the picture inverts. In London, and across much of the South East, Surrey, Hertfordshire and the more desirable parts of the South West, a modest two-bedroom flat can cost £350,000 to £500,000 while renting for perhaps £1,400 to £1,900 a month. That gives gross yields closer to 3.5% to 4.5%, sometimes lower once service charges on flats are counted.

What buyers are paying for is scarcity, employment density and a long record of price growth. Historically, these areas have rewarded patience with capital appreciation rather than cash flow, and many investors accept a modest monthly surplus — or even a small shortfall — on that basis.

Before going down that road, be honest about whether you can fund a shortfall for several years. If the rent barely covers the mortgage, an interest rate rise or a boiler replacement comes straight out of your pocket.

Void periods: the quiet killer of returns

Empty weeks are where optimistic spreadsheets go wrong. If a property rents for £900 a month and sits empty for four weeks a year, you have lost roughly £830 of income — around 8% of the annual rent. In weaker markets, void periods of six to eight weeks between tenancies are not unusual, and they tend to cluster in winter, exactly when you least want them.

Areas with a large, transient rental population — student towns, areas with heavy short-term contract work, pockets of older housing stock with few amenities — show higher turnover. Areas with family housing, good schools and stable employers show the opposite. Ask a local letting agent what average void periods look like for the type of property you are considering, and ask them to explain how they measure it. Some quotes count only days between tenancies; others conveniently exclude refurbishment time.

Tenant turnover also brings real costs: re-advertising, referencing, a fresh inventory, and often a week or two of cleaning and small repairs. Budget for it rather than hoping it will not happen.

Turning gross yield into something you can trust

Take a £140,000 two-bedroom terrace in a northern town. Rent at £800 a month gives £9,600 a year, a gross yield of 6.9%. Now subtract:

• Letting agent fees at 10% including VAT: about £960
• Landlord insurance: around £250
• Gas safety certificate, electrical checks and servicing: £200
• An allowance for repairs and eventual replacement of the boiler, kitchen and bathroom, say 1% of value: £1,400
• Four weeks of void: roughly £740

That is around £3,550 of costs, leaving roughly £6,050 before mortgage interest and tax — a net yield closer to 4.3%. Add a mortgage and the taxable profit narrows further. The same exercise on a London flat at 4% gross can easily produce a net yield below 2%.

Do this for every area on your shortlist. It is the single most useful hour you will spend, and it stops you falling in love with a headline figure.

Judging an area over ten years, not one

Long-term performance comes down to the fundamentals of a place. Look for a spread of employers rather than one dominant industry, a population that is stable or growing, and housing stock that matches what local people actually want to rent — family homes near schools, or well-connected flats near transport and hospitals.

Check the local plan for large new housing allocations, which can soften rents for years, and for infrastructure that genuinely improves access. Consider how tightening energy efficiency rules for rented homes may affect older, poorly insulated properties in your area; a cheap house with an ancient boiler may need thousands spending on it before long.

Finally, match the area to your own aims. If you want monthly income, the higher-yielding regions of the North, Midlands and Wales usually serve you better. If you want growth and can absorb thin cash flow, the South has the stronger record. The worst outcome is buying one while expecting the other.