Void Periods: What an Empty Month Really Costs, and How to Shorten It
2026-11-11
Every deal analysis has a line for voids, and most of them are guesses. "Two weeks a year" or "5% of rent" goes into the spreadsheet because that's what everyone uses — and then a single bad changeover wipes out a year's profit.
Voids deserve better than a rule of thumb. This guide shows what an empty month actually costs, how to turn that into a void allowance you can defend, and how to keep the gaps short.
What a Void Actually Costs
The obvious cost is the lost rent. The less obvious costs arrive at the same time — because when the property is empty, its running costs become yours.
For a property let at £900 a month, a one-month void with a change of tenant looks like this:
| Cost | Amount |
|---|---|
| Lost rent | £900 |
| Council tax while empty | £130 |
| Utilities and standing charges | £60 |
| Cleaning between tenancies | £200 |
| Touch-up decoration and small repairs | £300 |
| Inventory and check-in | £150 |
| Letting fee for finding the new tenant | £600 |
| Total cost of the changeover | £2,340 |
The mortgage, insurance and service charge carry on as normal — they're in your costs whether the property is let or not. But the line above is cash you only spend because the tenant changed.
A one-month void costs about 2.6 months' worth of that month's rent. That's why the length of the gap matters less than you'd think — the fixed costs of a changeover are there whether it's empty for a week or a month.
[!note] Council tax when empty When a property is empty and unfurnished, the owner is normally liable for council tax. Discounts and exemptions are set locally, and councils can charge a premium on homes left empty for a year or more. Check your council's policy before you budget.
Turning Voids Into an Allowance
A void allowance should come from two numbers: how long tenants typically stay, and what each changeover costs.
Annual void allowance = Cost of one changeover ÷ Years between changeovers
| Typical tenancy length | Annual allowance (at £2,340 per changeover) | As % of annual rent |
|---|---|---|
| 1 year | £2,340 | 21.7% |
| 2 years | £1,170 | 10.8% |
| 3 years | £780 | 7.2% |
| 5 years | £468 | 4.3% |
Two things stand out. First, a property with high turnover — student lets, short corporate lets, a poor-quality flat that tenants leave quickly — needs a far bigger allowance than the standard 4-5%. Second, tenant retention is worth real money. Keeping a good tenant for five years rather than two saves around £700 a year on this property alone.
Since the Renters' Rights Act, tenancies are periodic and tenants can leave on two months' notice at any time. Turnover is now driven by how happy your tenants are, not by a fixed-term end date. See what changed under the Renters' Rights Act.
Put your own changeover cost and tenancy length into a projection and see what it does to the long-run return:
:::tool cashflow-projection Model Voids in Your Cashflow :::
How to Shorten the Gap
1. Start Marketing the Day Notice Arrives
A tenant's two-month notice is two months of marketing time. Agree viewing arrangements with the outgoing tenant early — most are happy to help if asked politely and given proper notice — and aim to have a new tenant signed before the old one leaves.
2. Price at the Market, Not Above It
An overpriced property sits empty, and every week empty costs more than the rent premium you were hoping for. On a £900 property, asking £950 and waiting an extra three weeks costs over £600 of rent to gain £600 a year — and that's before the council tax and utilities. Check the evidence before you advertise:
:::tool rental-market Check Market Rents by Postcode :::
3. Do the Work Between Tenancies Quickly
Have your cleaner, decorator and handyman lined up before the move-out date. A changeover that needs three trades booked from scratch is where a one-week void becomes a five-week void.
4. Keep the Compliance Paperwork Current
You can't let a property without a valid gas safety record, EICR and EPC. Discovering an expired certificate on move-out day adds a week while you get an engineer in. Track the expiry dates and renew ahead of them.
5. Look After the Tenants You Have
The cheapest void is the one that never happens. Fix repairs promptly, keep rent in line with the market rather than pushing it to the limit, and answer messages. A tenant who feels looked after stays — and on the numbers above, that's worth hundreds of pounds a year.
Voids in Your Deal Analysis
When analysing a purchase, use a void allowance built from the property's likely tenant profile, not a standard figure:
- Family house in a stable area: 4-5% of rent
- One- and two-bed flats for young professionals: 6-8%
- HMO rooms: 8-10% per room, depending on demand
- Student lets: budget for the summer gap explicitly
If a deal only works with a 2% void allowance, it doesn't really work.
:::tool deal-analyser Analyse a Deal With Realistic Voids :::
Summary
- A one-month void with a changeover costs around 2.6 times the month's rent once cleaning, repairs, letting fees, council tax and utilities are added
- Annual void allowance = Changeover cost ÷ Years between changeovers
- High-turnover properties need allowances well above the standard 4-5%
- Start marketing on notice, price at market, line up trades in advance and keep certificates current
- Tenant retention is the most valuable void strategy there is
Voids are the cost most landlords underestimate and most can control. Measure them honestly, and they become a number you manage rather than a surprise.
This guide is for educational purposes only. Costs vary by area, property and agent — use your own figures in your analysis.