The sixty-second answer
Because the failure happens before your phone rings, so you cannot see it. Six faults produce this complaint: a phone that stopped being reachable, all lines busy, voicemail nobody checks, after-hours rules starting early, a failing forward to a mobile, or a wrong number published somewhere. Test by calling yourself from outside.
Why this complaint is worse than a dropped call
When a call drops, you know. You were on it. When a customer cannot reach you at all, you learn about it weeks later, from the one person annoyed enough to mention it, and only if they bother coming back. Everyone else simply called somebody else.
That is what makes this the most expensive fault in small business telephony. It is silent, it is invisible from inside the building, and it produces no evidence. Your phone sat there all afternoon looking perfectly healthy. The revenue side of it is worked through in what missed calls cost a Canadian small business; this page is about finding the cause.
Cause one: the phone stopped being reachable
A phone on a modern system does not sit passively waiting. It keeps telling the system where it is, re-registering periodically so that the system holds a current binding between your business identity and the device you are actually reachable at, and it is that binding which incoming calls are routed against [1].
When the binding lapses — the internet blipped overnight, a router rebooted, a firewall rule changed, someone unplugged a switch to vacuum — the handset does not tell you. It still lights up. It still shows the right time. You can still dial out on it. It just cannot be reached. This is the single most common cause of "I called and it rang and rang", and it is why a phone that looks fine proves nothing.
Cause two: everything was busy
If your system can carry a limited number of simultaneous calls and all of them are in use, the next caller gets a busy tone or drops straight into voicemail. Nobody's phone rings, because there was nothing left to ring on. From the inside, three people were on the phone and everything worked. From the outside, you were closed.
This one has a distinct fingerprint: complaints cluster at your busiest hour, and never at 3pm on a Wednesday. Sizing is covered in how many phone lines your business needs, and the caller's experience of it in why callers get a busy signal.
Cause three: the call arrived and died in voicemail
A call that reaches a voicemail box nobody opens is, to the customer, identical to a call nobody answered. Worse, they think they have done their part and are waiting on you.
Check three things today. Is the box full? A full box either rejects messages or plays an error, and neither reads as a functioning business. Is the greeting current? A greeting naming an employee who left in 2023, or promising hours you no longer keep, does more damage than no greeting. And do messages reach a human the same day? If checking voicemail is a task assigned to nobody in particular, it is a task done by nobody in particular. Routing messages to email is the standard fix and is covered in voicemail to email for Canadian businesses.
Cause four: your after-hours rule is wrong
Time rules are set once and then never re-read. The common failures are a closing rule that starts an hour before you actually close, a rule still set for last year's summer hours, a statutory holiday list that ended two years ago, and a time zone that was never set correctly in the first place.
Each of these produces exactly the reported symptom: a real customer, calling during what they believe are your hours, hitting a closed message. Nothing in your building indicates anything is wrong. Options and sane defaults are in after-hours and holiday call routing.
Cause five: the forward to a mobile
Small businesses forward the office number to a cell phone constantly, and it is the least visible failure path in the whole chain. The office system did its job and handed the call off. What happened next — the cell had no signal in a basement, the mobile voicemail answered before your business greeting could, the phone was in Do Not Disturb, the call was silently screened — is not something your phone system can see or report.
The fix is not to abandon mobiles. It is to stop chaining forwards, and instead present the same business identity on the desk phone and the mobile at once so both ring together. A user is not limited to registering from a single device [1], which is the technical reason that works. The practical version is in answering business calls on your cell phone.
Cause six: they dialled a number that is not yours any more
This one is nobody's fault and it is everywhere. An old number on a directory listing you forgot you created. A digit transposed on a vehicle wrap. A previous owner's number still on a supplier's website. A number that was correct before you moved offices.
Search your own business name and look at every number that appears. Check your online map listing, your industry directories, your invoice template, your email signature, your printed material, and any listing a franchisor or association maintains for you. It is dull work and it routinely finds at least one dead path.
The audit that finds your fault in an afternoon
Take a mobile that is not connected to your office network. Then call yourself, deliberately, from outside:
Call the main number during business hours and count the rings before anything happens. Call every direct number you publish. Call the number on your website, then the one on your invoice, then the one on your vehicle or signage, then the one in your online listings — treating them as separate tests, because they are. Call once at your busiest hour. Call once at lunch. Call once fifteen minutes before you close, and once fifteen minutes after. Leave a voicemail and see how long it takes to reach a human. Then have someone try from a landline, and someone else try from a different mobile network.
Write down what happened each time. Most businesses doing this for the first time find at least one broken path, and the pattern points straight at the cause: failures at one time of day mean capacity or hours, failures on one published number mean a wrong listing, failures on everything mean registration, and calls that connect but sound bad mean the network rather than the phone system.
That last distinction is worth keeping straight. Audio damage is a network problem: live voice is carried by a protocol that does not guarantee delivery, does not prevent out-of-order delivery, and does not assume the network beneath it is reliable [2], and delay compounds it — ITU-T guidance treats one-way delay as having a real ceiling, recommending that 400 ms not be exceeded for general planning and noting that highly interactive tasks are affected below that [3]. Long before a call fails, two people are talking over each other and describing the phone as broken. Diagnosing that is a separate job, covered in why business calls keep dropping and bandwidth and quality of service requirements.
One thing most businesses never test
Try reaching yourself the way a customer with a hearing or speech disability would, or a customer using a relay service, or a customer who cannot navigate a spoken menu quickly. The Accessible Canada Act sets the purpose of a Canada without barriers on or before January 1, 2040, through the identification and removal of barriers in areas that expressly include information and communication technologies [5]. A menu that requires fast keypresses, a greeting spoken too quickly, or a system with no route to a human are all barriers, and they generate exactly the same complaint: I could not reach you. Menu design that avoids this is covered in auto attendant design for small businesses.
Where we sit
We run hosted phone systems for Canadian businesses, and the part of this we control is the part that should never be invisible: registrations that recover on their own, capacity that does not run out at your busiest hour, hours and holidays that are actually correct, messages delivered to email rather than parked in a box, and desk and mobile ringing together instead of chaining forwards.
What we do not control is the number printed on a directory listing you made in 2014. What we will do is run the outside-in audit with you and tell you plainly which of the six causes you have, because most of Canada's 1.08 million small businesses [6] have nobody on staff whose job that is. If a provider tells you they will fix your reachability, ask what they tested on your site: a performance claim has to rest on an adequate and proper test, and the burden of proving it is theirs [4]. Our pricing is published on the pricing page, so you can weigh it before you talk to anyone.