Landlords starting or building their buy-to-let portfolios may have been clamouring to beat the Stamp Duty deadline in March, but this has helped boost existing property investors, agents have claimed.

The latest Buy to Let Index from Your Move and Reeds Rains, shows the March rush to complete buy-to-let transactions means landlords sitting pretty will have seen total returns rise to 12.2% year-on-year.

This is up 10.7% from February and is also the fastest annual rate of return for existing landlords seen since November 2014, when the same measure last reached 12.3%.

While property prices may have increased, boosting total returns, rental yields have actually dropped from 5.1 % last year to 4.9% in March, the index reveals.

In slightly more concerning data for landlords and lettings agents, paying the rent on time has become slightly more of a challenge for tenants in March. Across England and Wales the overall level of rental arrears now stands at 9.1% of all rent due in the private rented sector, compared to 8.8% in February 2016.

That is also up from 7.4% in March 2015, although this is still lower than the all-time arrears high of 14.6% in February 2010.

Tenant finances have also felt a setback compared to the same point last year. The latest arrears rate of 9.1% compares with 7.4% rent arrears in March 2015.

Adrian Gill, director of Your Move and Reed Rains, said: “Landlords need tenants with sound finances, and tenants need a property they can afford. While there is always room for healthy negotiation on rents, both landlords and tenants need each other to reach a deal. So some of the language of confrontation between landlords and tenants is not healthy or constructive.

“For private renting to remain an affordable option and a high-quality home for millions, the answer is more supply and more choice. That means lifting the barriers to investment in property, rather than adding fresh penalties for landlords aspiring for their own financial security.

“Good landlords also understand that their interests and the interests of their tenants are aligned – a tenancy should be a mutually beneficial deal.”