The 63 per cent figure was up by 15 per cent from June, which was the previous record high, and was the third straight month in which a new record has been set.
The number of agents reporting rent rises is more than double the 31 per cent recorded last July, which was the same figure for July 2017.
David Cox, chief executive of ARLA Propertymark, noted that the trade body had warned that rents would rise once the Tenant Fees Act came into force.
He continued: “The fees agents have been banned from charging are still being paid for by tenants, however it’s now through their rent, rather than upfront costs.”
The report found that the average number of properties under management per branch dropped to 184, down from 199 in June. Despite the fall in supply, demand grew from 70 prospective tenants registered per branch to 73.
This is still down from the 79 registered per branch in July last year.
Meanwhile the number of landlords exiting the market entirely remained at four per branch, unchanged from last year.
Cox continued: “The fall in the number of properties available further increases competition in the market, which only pushes rents up or forces landlords to exit the market entirely. As the sector faces increased levels of legislation, it’s evident this is putting even more pressure on the industry.”