The comments come as the Bank of England rate hike to 5.25 per cent has pushed up the price of mortgages, leaving thousands struggling with repayments.
Landlords, particularly those who are inexperienced in the lettings market, could get into difficulty with an increased number of house repossessions and greater debt expected.
Malcolm Harrison, spokesperson for the ARLA, said: “When you keep having interest rate rises there is a bit of a ‘drip-drip’ principle that makes people wonder about affordability.
“Having said that, most buy-to-let investors actually do their sums quite carefully, give themselves a cushion and work it out according to the interest rates.”
He added that those considering a buy-to-let property should prepare for the possibility of another interest rate rise this year and work out their mortgage according to estimations.
They will then be in a better position to judge whether their current rent is going to be enough to cover this figure.