Answering service cost comparator

Answering services rarely quote a single flat per-call rate. Most charge a base monthly fee that includes a bundle of calls, then a separate rate for anything beyond it. The advertised "per call" figure usually refers to that overage rate, not the blended cost once the base fee and actual volume are both factored in — and those two numbers can be a long way apart.

Why the headline rate understates it

At low volume, a base fee that isn't fully used drags the real cost per call up well above the quoted rate — paying £150 for an allowance of 50 calls when only 20 come in means each of those 20 calls actually costs £7.50, not whatever the marketing page led with. At high volume, once the included allowance is used up, every extra call adds the overage rate on top, and the blended cost creeps back up towards that headline figure from the other direction. The true cost per call only sits still around the volume the plan was actually designed for.

A worked example

A £150 base fee covering 50 calls, £3 for each call beyond that, and 80 calls actually answered in a month: 30 calls run over the allowance, adding £90, for a total of £240. Spread across all 80 calls, that's £3 a call — matching the overage rate exactly at this particular volume, but that's a coincidence of the numbers chosen, not a rule. Lower the volume to 40 calls and the same £150 base fee spreads to £3.75 a call, with no overage involved at all.

What this isn't

This works from whatever base fee, allowance and overage rate are entered — it's a comparator built from a quote already in hand, not a claim about what any specific provider charges. It also doesn't account for setup fees, minimum contract terms, or how "answered" is defined by a given provider, which varies and is worth checking against the actual contract before signing.