Spending less than 30% of gross income on rent is no longer an attainable affordability threshold for many under 30s, according to new data from flatshare site SpareRoom.

Government wage data puts the gross median annual wage of 18-21 year olds working full-time at £22,001 (£1,833 per month) and £31,200 (£2,600pm) for 22-29 year olds. That means, according to the ‘30% rule’, rent budgets should not exceed £550pm and £780pm respectively. For an under 30 earning £26,600 (£2,217pm) – the mid-point between the median salaries for each age group – the monthly rent budget would be £665.

The monthly budget (£780) for 22-29 year olds is enough to cover the UK average room rent (£753pm), but falls far short of the London average rent (£995pm) by £2,580 per year. A middle-earning under 30 with a budget of £665pm would have to ‘find’ an additional £1,056 per year to cover the UK average rent.

One of the perks of flatsharing is flexibility and yet, based on the 30% threshold, young renters are far more limited when it comes to where they can afford to live. 

The average budget of 22-29 year olds (£780pm) excludes them from living in London, Edinburgh, Oxford, Bath and Cambridge. Far more limited are the options of working 18-21 year olds. Their average budget (£550pm) is £2,436 per year lower than the UK average room rent of £753 per month. They are excluded from most major cities but could afford to rent in 12 cities including Liverpool, Swansea, Sheffield, Wolverhampton and Aberdeen.

One third of men and 22% of women aged 20-34 years old lived with their parents in 2024, and the overall number rose 9.9% in the decade from 2014². The number of 16-24 year olds actively seeking work but who are not in education, employment or training is rising too.

At the same time, renters aged 18 to 24 are decreasing. In 2014, this age group made up around a third (32%) of the users on SpareRoom. A decade later, this had dropped to just over a quarter (27%). As for 25-34 year olds, they made up 45% of the flatshare market in 2014, a figure that had dropped to 42% 10 years later, as the presence of older age groups in the market increased.

The cost of living is putting pressure on under 30s who’ve already managed to fly the nest. In an August 2025 survey of 3,775 renters by SpareRoom, 22% of under 30s had used overdrafts and 17% had taken on second jobs to help pay their rent – higher figures than older age groups.

Renters under 30 are also more financially reliant on parents and relatives. Over a quarter (26%) had received a deposit loan to help them start renting in the first place, showing just how hard it is to leave home at all. Almost a fifth (19%) had needed financial help to meet their monthly rent payments.

SpareRoom director Matt Hutchinson says: “In reality, the 30% affordability rule has been unrealistic for a long time. When rents are 40% or even 50% of income, as is more common today, affording them is challenging and saving for a deposit is out of the question. This doesn’t just delay life plans. 

“If you can’t meet unexpected costs outside of normal expenditure then you’re more prone to debt. And when disposable income is severely reduced there are knock-on effects for mental health and loneliness. So this is more than a problem for renters, it’s a problem for the economy and for society too.

“It’s not only sky-high rents that exclude more under 30s today; there are other barriers to entry. Not everyone can save a deposit equivalent to five weeks’ rent and many parents can’t afford to help either. The Renters Rights Bill seeks to ban the practice of asking for rent in advance – sometimes as much as 12 months’ worth – which will level the playing field. Tenants will also be able to challenge annual rent increases, which can be reduced if the proposed rent is deemed to be above the market value. But that doesn’t tackle the biggest challenge of all which is that market-value rents are already way too high.”