London void costs reach £1,357 per let as average vacancy period extends to 23.2 days

London landlords are now losing £1,357 on average each time a property sits empty, according to Rushbrook research reported by Landlord Today on 1 October 2026. That is the highest regional void cost in England. Nationally, the average cost of a void has risen 57.5% since 2023, from £696 to £1,097, while the average void period has increased from 17.5 days to 23.2 days.

The practical point is straightforward: there is no new legal deadline in this update, but avoidable delays are becoming more expensive. In London, where rents and contractor costs are typically higher than in most regions, an extra week off-market can wipe out much of a year’s rent increase. For a landlord with one flat, that is a direct hit to cash flow. For a portfolio landlord with several turnovers in a quarter, it becomes an operating issue that needs managing like arrears.

Bring re-letting work forward by two to four weeks

The first process change is to treat the final two to four weeks of a tenancy as the re-letting window, not dead time. Book a pre-end inspection before the tenant leaves, identify cleaning, repairs and redecoration, and confirm contractor availability before check-out day. If you wait until keys are returned, you join the same queue for cleaners, decorators and handymen as everyone else. In boroughs with older housing stock and heavier licensing conditions, such delays can quickly spill into missed compliance checks and slower remarketing.

Check certificates and licence status before advertising

A significant number of re-lets are delayed not by demand, but by paperwork. Before marketing, confirm that you have:

• a valid gas safety certificate where the property has gas
• an in-date EICR where required
• a valid EPC for marketing and letting
• working smoke alarms and carbon monoxide alarms installed where required

If the property is an HMO, or is in a borough with additional or selective licensing, check the licence position and any conditions affecting occupancy, room use or amenity standards. None of these duties is new, but if one has lapsed, turnaround can stretch from days into weeks.

Start marketing earlier where access allows

If a tenant has given notice, begin a pre-marketing campaign two to four weeks before the property becomes vacant, provided access arrangements and tenancy terms allow. In London, this matters because demand is highly local. A one-bed in Wimbledon, Clapham or Canary Wharf may let quickly if priced correctly, while a larger flat in a slower micro-market may need better presentation or a rent adjustment within the first seven days of listing. Virtual viewings, floorplans and a complete compliance pack can save time because applicants and agents are not waiting for basic information.

Reprice quickly if demand is weak

Pricing discipline is critical. The Rushbrook figures show void losses rising faster than many landlords expect, and one common mistake is holding out too long for an optimistic rent. If a property has low enquiry levels or weak viewing-to-offer conversion in the first week or two, reprice quickly. In practice, losing £50 to £75 per month on headline rent is often cheaper than carrying a void for another seven to 10 days, especially in London where the average void cost is already £260 above the national figure.

Do not let deposit administration delay the turnaround

Deposit handling is another area where landlords create avoidable delays. Check-outs should be documented with a clear inventory, meter readings, key records and dated photographs on the day the tenancy ends. Deposit deductions should be evidenced and raised promptly through the relevant scheme process. If disputes drift, cleaning, repairs and contractor access can be delayed. The legal duty is established: deposits must be protected correctly, and returns or disputes must be handled under scheme rules. The operational point is that weak deposit administration can add a week to turnaround for no good reason.

Measure void performance every month

For portfolio landlords, this needs tracking monthly. Monitor:

• average void days
• void cost per property
• time from notice to marketing
• time from check-out to new tenancy start

If your average turnaround is above the reported national figure of 23.2 days, identify where time is being lost: contractor lead times, pricing, compliance paperwork or agent response times. Set a target such as reducing average turnaround by three to five days over the next quarter. On London rents, that can recover a meaningful amount of annual income.

Insurance may help with cash flow, but not with preventable delays

Insurance is worth reviewing, but it is not a substitute for process. Some landlords may want to consider loss of rent or rent guarantee products where cash flow is tight, particularly if they hold highly leveraged stock or depend on one or two units for income. Check policy terms carefully: many products do not cover every type of vacancy, and they will not fix a preventable delay caused by expired certificates or slow decision-making.

Three actions to take this month

First, create a re-letting checklist and use it for every property with notice already served or due to end in the next 90 days.

Second, line up preferred contractors now and agree target response times for cleaning, safety checks and minor repairs.

Third, ask your agent or property manager for the last 12 months of void data by property and borough, then reprice or rework the slowest-turning units before winter demand softens further.

This article is general information, not legal or tax advice.