Industry studies put small-business missed-call rates around 25-40% of inbound calls, and the behavior after the miss is the expensive part: roughly 80% of callers who hit voicemail don't leave a message, and most call a competitor within the hour. For a local service business, the caller found you on Google next to four alternatives, the phone IS the funnel.
Run your own numbers instead of trusting ours: take your average job or customer value, count the calls you get per week, assume a third go unanswered and most of those don't call back. A plumber averaging $400 jobs who misses five calls a week is leaking roughly $1,500-2,000 a week in bookable work, $75,000+ a year, against a phone bill of maybe $150 a month.
The fix isn't heroic availability, nobody answers 100% of calls with human beings, it's making sure a miss isn't a dead end. Calls that ring your cell as well as the desk cut misses immediately. An AI receptionist takes the rest: the after-hours calls, the both-lines-busy calls, the Saturday calls, answered, captured, and texted to you while the customer is still deciding who to hire.
Every business we've set this up for is surprised by the same thing: not the after-hours volume, but how many calls were being missed during business hours all along.