You commute to the office five days a week, wearing thermals. Your flatmate works from home in shorts with the heating on full blast. At the end of the month, you split the gas bill 50/50.
That's not a fair split — that's you subsidising your flatmate's tropical home office. And with the average UK household spending over £2,500 a year on energy, the difference adds up fast.
The good news: splitting utility bills fairly when working from home is straightforward once you have the right method. This guide explains exactly how to do it — and gives you a free calculator to settle it in under two minutes.
The average UK employee working from home full-time adds an estimated £500–£700 per year to household energy costs (Citizens Advice, 2023). That extra cost breaks down across four main areas:
When your flatmate uses significantly more of these resources than you do, a 50/50 split on utility bills isn't fair — it's just easy. And in a cost-of-living crisis, easy doesn't cut it.
The fairest way to split utility bills when working from home is by the number of days each person spends at home during working hours:
If you're in the office all week and your flatmate is home all week, the split is clear. If you're both hybrid, the formula still works — just use each person's average weekly WFH days.
Split the variable bills (heating, electricity, water) entirely by WFH days. The office worker contributes nothing extra to the bills driven by daytime usage. This is the most mathematically fair approach, but can feel brutal if one person ends up paying a much larger share.
Split half the bill equally — this covers standing charges and base usage that both flatmates benefit from regardless — and split the other half by WFH days. This is the "let's still be friends" approach. Both people pay something, but the heavier home user pays proportionally more.
Example: Monthly heating + electricity bill: £200. Person A: WFH 5 days/week. Person B: office 5 days/week.
| Method | Person A (WFH) | Person B (Office) |
|---|---|---|
| 50/50 (current) | £100 | £100 |
| Pure WFH split | £200 | £0 |
| Hybrid method | £150 | £50 |
Most flatmates land on the hybrid method — it's fair enough to be defensible and kind enough that nobody storms off.
| Include ✅ | Exclude ❌ |
|---|---|
| Gas / heating | Council tax (fixed, everyone benefits equally) |
| Electricity | TV licence (fixed cost) |
| Water | Streaming subscriptions (used equally) |
| Broadband (usage portion) | Rent (unrelated to WFH usage) |
The logic is simple: if a bill goes up because one person is home more, they should pay more of it. If the cost is fixed regardless, split it equally.
Most people now work a mix of home and office days — typically 2–3 days at home per week. The same formula applies: just use each person's average weekly WFH days as the basis for the split.
Example: Person A WFH 3 days/week, Person B WFH 2 days/week. Total household WFH days = 5.
The WFH Utility Adjuster calculates this automatically — enter each person's days and it does the rest.
Worth knowing before you have the conversation: HMRC allows employees who work from home to claim £6 per week in tax relief on home office costs without needing receipts (2024/25 rate). That's £312/year back from the government. Your flatmate may already be recouping some of their extra bills through their tax return — which makes the adjustment conversation considerably less painful for everyone.
The key is to lead with numbers, not feelings:
Hard to argue with a number. Much easier to argue with "I feel like I'm paying too much."
If they're resistant, suggest the hybrid method as a compromise. You'll both end up paying something fairer than 50/50 without it feeling punitive.
With hybrid working now the norm for around 28% of the UK workforce (ONS, 2024), the days of identical commuting patterns in a house share are largely gone. Flatmates increasingly have very different home usage profiles — and their bill splits should reflect that.
The WFH utility adjustment isn't a niche concern anymore. It's a standard part of fair flatsharing. The sooner it becomes a normal conversation to have when moving in together, the less resentment builds up later.
Fair doesn't mean equal. It means proportional. And now you have the tool — and the argument — to prove it.