Rental yields have fallen by nearly 20 per cent since 2011, a survey by the National Landlords Association suggests.

The group found that average yields have come down from 6.7 per cent to 5.4 per cent over the past nine years, according to a poll of its members.

This represents a drop in income of more than £19,000 based on the average NLA member’s portfolio, which is worth just under £1.5m.

Landlords with larger portfolios of 20 or more properties have seen the biggest fall in income as their yields have fallen from an average 7.7 per cent less than a decade ago to 5.8 per cent today – a reduction of almost a third.

The NLA says that the cost of building and running a buy-to-let portfolio has increased significantly over the past decade, following changes to tax relief for landlords and the stamp duty surcharge on additional properties.

But it says typical monthly rents have not kept pace with inflation over that time. 

Since 2011, average house prices have increased by 40.2 per cent while rents have risen by only 14.5 per cent.

NLA chief executive Richard Lambert says: “Although it is popular to paint private landlords as greedy parasites, only interested in pushing rents as high as they can go, the fact that rents continue to track below inflation, and far behind house price inflation, illustrates that this is far from the case.

“Being a landlord in the UK remains a worthwhile, and potentially profitable endeavour, but it is not a means of turning a quick profit. 

“Anyone planning for future investments should think very carefully about their options and maintain realistic expectations of a reasonable return.

“A long-term strategy is essential, as is a commitment to providing a high quality service.”