The cost of downtime is almost always higher than the figure a business first puts on it. Most owners work it out by taking the revenue they would have earned during the hours they were shut, and stopping there. That calculation misses the wages still being paid, the orders that arrive late, the stock that spoils and the customers who quietly go elsewhere.
Key Takeaways
- UK businesses lost 50 million hours and £3.7 billion to internet failures in 2023.
- The same outage cost five times more in 2023 than in 2018.
- 850,000 UK firms lose money the moment connectivity fails.
- Lost revenue is only the visible layer; wages, penalties, spoilage and lost trust follow.
- A basic formula usually doubles the figure owners first assume.
- Protecting a few critical systems is affordable once you know your hourly cost.
The national numbers give a sense of the scale. Research by the business internet provider Beaming found that UK businesses lost over 50 million hours and £3.7 billion to internet failures in 2023, across 8.8 million separate incidents. What makes that figure interesting is not the total but the trend behind it: the hours lost were down from 60 million hours in 2018, yet the cost rose fivefold, from £742 million to £3.7 billion. Businesses are going down less often and paying far more each time it happens.
Why the Same Outage Costs More Than It Used To
The reason is dependence. Trading, payments, stock systems, customer records and internal communication now share the same infrastructure, so one failure stops several revenue streams at once. Beaming found that around 15% of UK businesses, some 850,000 firms, would start losing money the moment their connectivity fails.
During an eight-hour outage, the length of a normal working day, 39% of businesses would lose money, up from 34% at the end of 2018. That same Beaming data implies a median threshold of around six hours before employers start losing money, so a single morning’s disruption sits right on the threshold. These are 2023 figures, and dependence has only deepened since, so treat them as a conservative floor.
The Costs That Never Reach the Spreadsheet
Lost trading revenue is the visible layer. Underneath it sit several others that rarely get counted properly:
- Paid but unproductive staff time. Wages run on whether systems do or not.
- Missed deadlines and penalty clauses. Contracts and delivery windows do not pause.
- Damaged stock and equipment. Chilled goods and part-finished production runs.
- Recovery and overtime. Callouts, engineer time and weekend catch-up shifts.
- Customer trust. Hardest to price, often the most expensive.
Prolonged disruption can also squeeze cash flow from both ends, with invoices going out late while suppliers still expect to be paid on time. If customers begin to slip behind as a result, it is worth understanding your options around debt recovery during periods of economic uncertainty before the position becomes harder to unwind.
In manufacturing the picture is starker, because losses include scrapped material, restart costs and unmet order commitments on top of idle labour. In sectors like automotive, stoppages are widely reported to carry very high per-hour costs, though figures vary considerably by source and site.
A Simple Way to Calculate Your Own Number
A usable production downtime formula does not need to be complicated. Take your annual revenue and divide it by the number of hours you actually trade to get revenue per hour. Add the hourly wage cost of everyone who cannot work during an outage. Then add an estimate for recovery, spoilage and penalties.
Work it through with an example. A wholesaler turning over £2.4 million a year across roughly 2,400 trading hours earns about £1,000 an hour. Twelve staff on an average £18 an hour adds £216. Four hours down therefore costs around £4,900 before anything else, and that is the optimistic version.
Now add a chilled pallet written off, two deliveries that miss their slot, and a Saturday shift to clear the backlog. The same four hours comfortably clears £10,000. Run that twice in a year and the downtime risk starts to look like a line item worth managing rather than an accident worth shrugging at.
Power Interruptions as the Obvious Test Case
Electricity is the single dependency that takes everything else down with it. A brief interruption stops tills, servers, refrigeration, access control, machinery and the broadband router at once, and recovery always takes longer than the outage itself. It can also cut across essential office safety protocols, since emergency lighting, alarms and door systems all rely on the same supply.
Short outages are also the ones businesses plan for least, yet two hours at the wrong time of the morning can undo a week of scheduling. For operations where power continuity is critical, WBPS supplies, hires and maintains diesel and hybrid generators, UPS solutions, and CHP systems across the UK, covering a range of output sizes suited to everything from small commercial premises to industrial sites.
Spending on Resilience Before You Need It
Work out which parts of the operation genuinely cannot stop, then protect those first. For most businesses that is a short list, and a short list is affordable in a way that protecting everything is not.
Measures worth costing up include 4G or 5G failover, uninterruptible power supplies on servers and tills, and a standby generator where continuous electricity is non-negotiable. A written continuity plan and a tested backup regime cost little and save a great deal of confusion.
The case for spending is simply arithmetic. Once you know what an hour of downtime costs you, comparing that against the annual cost of failover connectivity or backup power is a straightforward decision rather than a leap of faith. Insurers and auditors increasingly expect that thinking to be documented too, so it is worth familiarising yourself with the key risk and compliance terms they may raise.
FAQs
Does Business Interruption Insurance Cover Downtime Costs?
It can, but policies vary widely in what they will actually pay out. Indemnity periods, specific exclusions and the requirement to evidence a financial loss mean many businesses receive less than they expected after a claim. It is worth reading the policy wording carefully and discussing any gaps with your broker before you need to rely on it.
What Is an SLA and What Happens if Downtime Causes a Breach?
A service level agreement sets out the uptime or delivery commitments a business has made to its customers or suppliers. If downtime causes a breach, the consequences depend on the terms agreed, but can include financial penalties, service credits, loss of the contract or lasting reputational damage.
How Often Should a Business Continuity Plan Be Tested?
Most continuity guidance recommends testing at least once a year, and again after any significant change to systems, premises or staff. A plan that has never been tested is unlikely to work smoothly under pressure, and gaps are far cheaper to find in a rehearsal than during a real incident.