How to Calculate What Missed Enquiries Are Costing Your Business

Most service business owners know they miss enquiries. A phone call during a busy appointment. A contact form submitted at 9pm on a Sunday. An email that arrived while the team was dealing with something else and never quite got replied to. The awareness is there. What is usually missing is a number — and without a number, the problem stays on the list of things to fix eventually rather than things to fix now.

This article gives you the calculation. It takes about ten minutes and usually produces a result that changes the conversation.

In short: Missed enquiries have a calculable cost — in lost revenue, in lifetime client value, and in the referrals that flow from the clients you never won. Running the numbers is the most useful thing you can do before deciding whether to fix the problem.

Step 1: Estimate how many enquiries you receive

Start with a realistic monthly figure for inbound enquiries across all channels: phone calls, contact forms, emails, direct messages, portal leads. Do not count existing client queries — only new or returning enquiries from people who have not yet committed.

Most service businesses underestimate this number because they only count the ones that were handled. The ones that arrived at 8pm and were never replied to do not appear in any record. A reasonable approach: take your confirmed enquiry count and add 20–30% for unread or unanswered contacts. If you have a contact form, check how many submissions came in over the last 90 days — the number is often higher than the team remembers.

For this exercise, call it N enquiries per month.

Step 2: Estimate your response rate

Of those N enquiries, what proportion received a timely, useful response? "Timely" means within the window where the enquirer was still actively considering their options — roughly one to four hours during business hours, and before the next business day for out-of-hours contacts.

Be honest. The answer for most small service businesses is not 100%. A realistic figure depends on your setup, but 60–80% is typical if you have one person managing enquiries alongside other work, and lower if the team is very small or very busy.

Call the missed proportion M%.

Step 3: Estimate your conversion rate on handled enquiries

Of the enquiries you do handle promptly and well, what share converts to a paying client? This varies by vertical — estate agents might see 10–20% of enquiries convert to instructions, a dental practice might see 50–70% of new patient enquiries book an appointment, a mortgage broker might convert 30–40% of engaged leads.

Use your own number if you have it. If not, use a conservative estimate.

Call this C%.

Step 4: Calculate monthly lost revenue

Here is the formula:

Lost clients per month = N × M% × C%

Then multiply by your average client value:

Monthly lost revenue = Lost clients × Average fee or first appointment value

Example

An estate agent receives 50 enquiries per month. They respond to 70% promptly — missing 30%. Of enquiries they do handle, 15% convert to an instruction worth an average fee of £3,800.

• Lost clients per month = 50 × 30% × 15% = 2.25
• Monthly lost revenue = 2.25 × £3,800 = £8,550

That is not a worst-case scenario. It is a mid-range estimate using conservative conversion and an average fee.

Step 5: Add the multiplier for lifetime value and referrals

The calculation above counts only the direct revenue from the missed client. It does not count:

• Repeat business — the seller who might become a buyer, the dental patient who attends twice a year for five years, the mortgage client who remortgages every two to three years
• Referrals — clients who would have recommended you to one or two others over the following year
• Reviews — the Google review that persuades the next ten people to make contact

A realistic lifetime value multiplier for a service business is 2x–5x the first fee, depending on the vertical and your retention rate. An estate agent who wins a seller as a client might also handle their purchase, their future let, and one referral — a chain worth £12,000–£15,000 from a single first instruction.

Apply this multiplier to your monthly lost revenue figure and the number becomes harder to ignore.

What the number usually means

For most service businesses that run this exercise, the monthly cost of missed enquiries falls somewhere between £3,000 and £15,000, depending on size and vertical. The response is often: "that cannot be right." The second response, when the calculation is checked, is usually: "we need to fix this."

The relevant question is not whether the number is exactly right — it is whether it is large enough to justify the cost of fixing the problem. A managed enquiry workflow that captures and qualifies most of those missed contacts has a cost. If the missed revenue calculation is ten times that cost, the decision is arithmetic, not judgement.

The audit you can run without any maths

If the calculation feels too uncertain, there is a simpler version: enquire through your own website or phone number at 7pm on a Friday and time what happens. Most business owners have never done this. The result is usually instructive. If the experience would not satisfy you as a potential client, it is probably not satisfying the real ones.

Frequently asked questions

What counts as a "missed" enquiry?

For this calculation, a missed enquiry is any contact that did not receive a timely, useful first response. That includes: unanswered phone calls, contact forms not replied to within one business day, emails that received an auto-responder but no substantive reply, and direct messages that were read but not answered within a few hours.

How do I find out how many enquiries I'm actually receiving?

Check your contact form submission records (most form tools log every submission, including ones not forwarded). Check your email inbox for any enquiry-type messages in the last 90 days, including ones that were never replied to. Pull your missed call log from your phone if available. Most businesses find the real number is higher than the remembered number.

Does the formula work for all service verticals?

The structure is the same. The numbers vary significantly by vertical — average fees, conversion rates, and lifetime value differ between a dental practice, a mortgage broker, and a trades business. Use your own figures where possible. If you are unsure of your conversion rate, start with a conservative estimate and note that fixing enquiry response usually improves conversion alongside capture.

What is a realistic timeline to see the impact of fixing this?

A managed enquiry workflow produces measurable changes within 30 days: response time data, enquiry capture rate, and the first qualified leads from the window that was previously unattended. The revenue impact — particularly for verticals with longer sales cycles like estate agents and mortgage brokers — builds over 60–90 days as those leads convert.