When landlords come to us, the same pattern comes up again and again. They have done their research. They know the asking rents on their street. They know what the portals say. But they have started from the wrong point entirely.
Property portals show you asking rents, not achieved rents. They show what landlords want, not what the market will actually pay. Confusing the two is one of the most expensive mistakes in property management, and if you are working out how much rent to charge, the portals are the wrong place to start.
Why asking and achieved rents differ
A portal is a shop window. Every listing on it is a landlord’s hope, and the listings that stay on it longest are, almost by definition, the ones priced above what tenants will pay. Well-priced properties let quickly and disappear. Overpriced ones linger, and they make the market look more expensive than it is.
Landlords also anchor. A flat that let for £4,000 a month in a stronger market is often re-advertised at £4,000 or more, whatever has happened since. In prime central London, where prices have fallen and rents have moved at different speeds in different streets, an anchor from two or three years ago can be badly out of date.
What overpricing really costs
In our experience across Kensington and Chelsea, a well-priced flat typically lets within about two weeks. An overpriced one can sit for six weeks or more.
At the borough’s average rent of £3,690 a month (ONS, August 2026), those 25 extra empty days cost around £3,000 in rent. That is roughly what a £250-a-month premium would earn in an entire year, and that is before the mortgage, service charge, council tax and bills that keep running while the property is empty. We explain the full cost in our guide to void periods.
Overpricing rarely ends with the rent you wanted. It usually ends with a price reduction after the property has gone stale, and a lower rent than if it had been priced correctly from day one.
How much rent to charge: finding the real market rent
1. Start with achieved rents, not asking rents
The most useful evidence is what comparable properties have actually let for in the last few months. A good local agent has this data from their own lettings. Indices that track new tenancies, such as HomeLet’s rental index, are a useful check on the direction of the market. ONS borough averages give context, but they include existing tenancies as well as new ones.
2. Compare like with like
Two flats on the same street can be worth very different rents. Adjust for:
- size in square feet, not just the number of bedrooms;
- floor level, lift and natural light;
- outside space;
- condition, kitchen and bathroom quality;
- furnished or unfurnished;
- energy rating and running costs;
- distance to the nearest station.
3. Read the live competition, carefully
Portals are still useful, just not as a price list. Look at how long similar properties have been advertised and whether their prices have been cut. A comparable flat that has sat for six weeks is telling you where the ceiling is.
4. Set a review point before you launch
Agree in advance what will trigger a price review. If a well-presented property has had few viewings in its first week to ten days, the market is giving you an answer. Acting on it early costs far less than waiting.
5. Price for the season
London rents rise and fall through the year. A property launched in a quieter month may need a sharper price, or a different plan, than the same property in a busy one.
Why pricing right matters more since the Renters’ Rights Act
Since 1 May 2026, three changes have raised the stakes on the starting rent:
- No more bidding wars. Adverts must state the rent, and landlords and agents can no longer accept or encourage offers above it. If you price too low, you cannot rely on competing tenants to push it up. If you price too high, the property simply sits.
- Rent increases are limited to once a year, using a Section 13 notice with at least two months’ notice, and tenants can challenge an increase at the First-tier Tribunal. The rent you start with sets the path for years.
- Tenancies are periodic. A tenant can leave with two months’ notice at any point. A tenant who feels they are paying over the odds is more likely to move on, which brings the next void closer.
The bottom line
The right rent is not the highest number you can advertise. It is the one that lets the property quickly to a good tenant, keeps them, and produces the best income over the year. That is a different question from “what are other people asking?”, and it needs different evidence to answer.
Find out how your rent compares
We offer a free Property Performance Review. We compare your achieved rent with the actual market rate, look at your void periods and your management costs, and tell you honestly where you stand. If everything is fine, you will know that with certainty. If there is room to improve, you will know exactly where.
Sources: ONS, Private rent and house prices, UK: September 2026 · HomeLet Rental Index · Gowling WLG, Renters’ Rights Act 2025: 1 May 2026