Average rents have risen by 4.3% over the past year to £1,369 per month, the latest quarterly index from Lomond has shown.
The network of lettings and estate agencies also found that tenants are now spending an average of 32.7% of their annual income on rent.
In London, average rents reached £2,418 per month, 76% above the UK average.
Average monthly rents in both the North West and Yorkshire rose by 5% year-on-year to £1,215 and £1,283 respectively.
Data from Goodlord and LomondIQ also shows the average UK renter is 31.5 years old.
Scotland has the youngest renters, with an average age of 25, which the Lomond attributes to its large student population.
Kent recorded a 5% increase in average rents, while the number of tenancies agreed in the county jumped by 121% over the past year.
Lomond chief revenue officer John Ennis says: “Our insights report shows that the rental market remains resilient, but affordability continues to be a key consideration for many households.
“With tenants now spending almost a third of their annual income on rent, the importance of delivering well-managed, high-quality homes in the right locations has never been greater.
“What we’re seeing across the UK is not a slowdown in demand, but a shift in renter priorities, with tenants increasingly focused on long-term value.”