Yet it is still possible to get yields of almost 8 percent in England and Wales by choosing your location carefully, according to new research from digital mortgage lender Molo Finance. It found that yields now average 4.98 percent across England and Wales but vary greatly depending on where you buy.

The gross yield on a property is calculated by dividing the annual rental income by the property’s price, which means that more expensive areas are often the least rewarding.

In Camden and the City of London the average property costs £672,104, and generates rental income of £2,268 a month. However, that gives investors a yield of just 3.58 percent a year, the lowest in the country.

This figure is calculated after taking into account purchasing costs such as stamp duty and conveyancing charges, as well as the purchase price. 

West Sussex, Dorset, Bromley North Yorkshire also offer low gross rental yields of 3.70 percent or less.

At the other end of the scale, the average property in the Central Valleys of Wales costs £100,706 and generates £697 a month in rent, giving a yield of 7.96 percent. That is more than double Camden’s yield.

Yields average 7.90 percent in Hartlepool and Stockton-on-Tees in the North East of England, 7.30 percent in Swansea and 7.06 percent in Coventry.

Figures from the National Residential Landlords Association show buy-to-let profits at a 16-year low and Molo chief executive Francesca Carlesi said this makes it even more important to get the best possible yield. “Of the top 10 places with high rental yields, all are either in the North, Midlands or Wales.”

There are some poor landlords out there and the Government is trying to improve the sector but tenants aren’t perfect either.

Rents in Wales are some of the cheapest of all averaging £791 a month. In the North, they average £889.

Aneisha Beveridge, head of research at Hamptons, said some landlords facing paying half their rental income on their mortgage, which they will find unaffordable. “They are likely to bow out, keeping upward pressure on rents.”

A decade ago landlords who remortgaged typically took the opportunity to borrow more money and invest it in further properties to expand their portfolio.

It is a different story today. As interest rates rise and look set to remain higher for longer than expected, more now opt to pay down their mortgage debt instead.

Despite this buy-to-let mortgage rates are starting to ease, slightly. The Mortgage Works recently cut its two-year fixed rate switcher mortgage to 4.94 percent. The deal charges a three percent fee and is available up to 65 percent loan-to-value (LTV).