Portsmouth among UK areas with the biggest increase in mortgage costs

Property prices have surged, interest rates have climbed, and monthly mortgage repayments now take a much bigger bite out of household budgets than they did in 2020. But have you ever wondered which parts of the country have seen mortgage costs rise the most over that period?

A new study by Mortgage Lane set out to answer exactly that, looking beyond headline house prices to focus on what buyers actually feel month to month. The study examined 58 major cities and large towns across the UK, comparing how average house prices and estimated mortgage repayments have changed between 2020 and 2025.

To do this, the study analysed average property prices for each location in both years, using publicly available UK housing market data, including Land Registry figures and national house price indices. Estimated monthly mortgage payments were then calculated for each city based on a consistent set of assumptions: a 20% deposit, a 30-year mortgage term, and typical five-year fixed mortgage rates. For 2020, an interest rate of 2.6% was used, reflecting the ultra-low borrowing costs of the time, while 2025 calculations assumed a rate of 4.9%, closer to what many buyers are currently facing.

By comparing the estimated monthly repayments from 2020 to those in 2025, researchers were able to calculate the cash increase homeowners would now be paying each month if buying the same “average” home. Cities were then ranked according to the size of that increase.

Portsmouth ranks 15th overall in the study, highlighting a clear rise in mortgage costs since 2020 as house prices along the South Coast continue to edge upwards. The average house price in Portsmouth increased from £169,704 in 2020 to £210,740 in 2025, which has pushed estimated monthly mortgage payments from £721 to £895. That represents an increase of around £174 per month, adding a noticeable strain to household budgets.

Meanwhile, London leads the ranking, recording by far the biggest increase in mortgage costs since 2020. Average house prices in the capital rose from £385,295 to £469,305, pushing estimated monthly mortgage payments up by £357, from £1,636 to £1,993. Brighton ranks in second place, where strong demand has driven prices up to £413,960 and added £314 a month to typical repayments. Bristol ranks third, with average house prices climbing to £322,067 and monthly mortgage costs rising by £282.

Bradford and Cardiff take fourth and fifth place, with monthly mortgage increases of £238 and £231 respectively, reflecting rising demand in both cities despite their different price points. Winchester ranks sixth, where buyers now pay around £222 more per month, while Glasgow comes seventh with a £213 increase as prices continue to rise in Scotland’s largest city. Preston and Wolverhampton rank eighth and ninth, both seeing monthly increases just over £210, driven by sharp price growth from lower starting points. Manchester rounds out the top ten, with average house prices rising to £246,332 and monthly mortgage payments increasing by £207.

At the other end of the scale, Southend-on-Sea, Carlisle, York, Lincoln, Canterbury, Tunbridge Wells, Birmingham, Chester and Peterborough recorded the smallest increases in monthly mortgage payments, all coming in under £50. While prices have still risen in these areas, the combination of more modest growth and local market conditions has helped limit the impact on borrowers’ monthly bills.

Commenting on the findings, Joseph Lane, mortgage expert at Mortgage Lane, said the results show just how dramatically the cost of borrowing has changed in a short space of time.

“Even in areas where house price growth has been fairly steady rather than explosive, higher interest rates mean buyers are paying a lot more each month than they would have in 2020,” he explained.

He noted that ultra-low rates during the pandemic years masked the true cost of rising house prices. “Back then, cheap borrowing softened the blow of higher prices. Now that rates have normalised, the full impact is being felt, especially in expensive or high-demand cities.”

He added that location plays a huge role in how hard buyers are hit. “Cities with strong jobs markets, good transport links and lifestyle appeal tend to see prices rise faster, which means larger mortgages. When rates increase, those larger loans translate into much bigger monthly jumps.”

Looking ahead, Lane urged buyers to focus on affordability rather than headline prices alone. “It’s not just about what a home costs, but what it costs you every month. Understanding how mortgage rates and local price trends interact is key for anyone thinking about buying in today’s market.”

The table below ranks the top 20 UK areas with the highest increase in estimated monthly mortgage payments since 2020: