How we estimate lost jobs
01What the counter is
The counter on our homepage is a modelled estimate, not a live measurement. It does not track real calls and it does not count any individual business. It spreads an estimated weekly total of jobs lost to voicemail across the week, using the London time of day, so the number you see climbs faster in working hours and slower overnight and at weekends. It resets at midnight, London time.
02The formula
weekly jobs lost = businesses × calls per week × share missed × share who leave no message × share that were new-job enquiries
| Input | Value | Status |
|---|---|---|
| UK construction businesses (small and medium) | 885,000 | Sourced: UK Department for Business and Trade / ONS business population estimates, start of 2025. |
| Inbound calls per business per week | 10 | Our assumption. Deliberately low. |
| Share of calls left unanswered | 25% | Our assumption. Published surveys span roughly 14% to 59%. |
| Share of those callers who hang up without leaving a message | 69% | Sourced: Moneypenny small-business call report. |
| Share of calls that are new-job enquiries that would have been booked | 10% | Our assumption. |
Result: 885,000 × 10 × 0.25 × 0.69 × 0.10 ≈ 152,663 jobs a week, roughly 21,800 a day on average across the UK building trades.
03When in the week
We split the weekly total by time of week using published platform data from field-service software (ServiceTitan, 2025, residential HVAC in North America, as reported by FieldCamp): about 88% of calls arrive Monday to Friday between 08:00 and 17:00, about 8.1% on weekday evenings and early mornings, and about 3.9% at weekends. Within each block, the hour-by-hour shape is our assumption, except that evenings cluster between 17:00 and 21:00, which is the published pattern.
| Hour (London) | Est. per weekday (Mon–Fri) | Est. per weekend day |
|---|---|---|
| 00:00 | 21 | 0 |
| 01:00 | 21 | 0 |
| 02:00 | 21 | 0 |
| 03:00 | 21 | 0 |
| 04:00 | 21 | 0 |
| 05:00 | 21 | 0 |
| 06:00 | 247 | 74 |
| 07:00 | 247 | 74 |
| 08:00 | 2,985 | 238 |
| 09:00 | 2,985 | 238 |
| 10:00 | 2,985 | 238 |
| 11:00 | 2,985 | 238 |
| 12:00 | 2,985 | 238 |
| 13:00 | 2,985 | 238 |
| 14:00 | 2,985 | 238 |
| 15:00 | 2,985 | 238 |
| 16:00 | 2,985 | 238 |
| 17:00 | 433 | 238 |
| 18:00 | 433 | 149 |
| 19:00 | 433 | 149 |
| 20:00 | 433 | 149 |
| 21:00 | 41 | 0 |
| 22:00 | 41 | 0 |
| 23:00 | 41 | 0 |
| Day total | 29,342 | 2,977 |
04Limits you should know about
- This is an estimate built from a few published figures and several assumptions. Change an assumption and the total changes in proportion.
- The call-timing data comes from US and Canadian heating and cooling companies, not UK building trades. We have no UK hour-by-hour data.
- Several of the sourced figures come from companies that sell call-answering services, so they have a commercial interest in the numbers.
- It does not describe your business. Your own call volume, missed-call rate and job value will differ, which is why the calculator on the homepage lets you put in your own numbers.
- It is not a forecast, and it is not a promise of what Vault and Key will recover for you.
05Questions or corrections
If you have better data, or think a figure here is wrong, email elliot@vaultandkey.com. We will update the model and this page together.