AMC vs CMC vs Warranty: Which Equipment Cover You Actually Have

A customer rang me last month about a £1,900 repair bill. The equipment was under contract. The contract didn't cover parts, and the failure was a part. Nobody had read the terms since signing, because nobody had needed to until that morning.

Warranty, AMC and CMC get used interchangeably in conversation all the time. They aren't interchangeable, and the difference turns up on an invoice at the worst possible moment.

The three, side by side

The single most consequential row is spare parts. An AMC that excludes parts on equipment whose failures are mostly component failures may cover very little of what you actually spend.

Warranty: what it does and doesn't do

A manufacturer warranty covers defects — the item was faulty, or failed in a way it shouldn't have within the period. It's included in the purchase price and it expires on a date.

It doesn't cover wear, misuse, accidental damage, or scheduled servicing. It also doesn't usually survive a repair by an unauthorised party, which is a common and expensive way to void cover without realising.

The practical failure with warranty is never the terms. It's that nobody knows the item is still inside the period at the moment a repair is authorised.

AMC: what you're buying

An annual maintenance contract is a paid agreement, usually renewed yearly, under which a provider services the equipment on a schedule and attends failures. Labour is generally included; parts are generally not.

AMCs make sense for equipment where scheduled servicing genuinely prevents failure, where downtime is expensive, or where a statutory inspection regime exists and you would rather a specialist owned it.

They make less sense for equipment that rarely fails, or where parts cost dominates and is excluded anyway.

CMC: the same, with parts

A comprehensive maintenance contract covers what an AMC covers plus spare parts. It costs more and shifts the risk of an expensive component failure onto the provider.

The decision between AMC and CMC is a straightforward expected-cost calculation: if the parts you expect to replace over a year cost more than the price difference, the CMC is cheaper. The difficulty is that most organisations can't answer what they spent on parts last year, per asset — which is itself an argument for recording actual repair costs against assets.

*Cover recorded per asset with its kind, provider, policy number and renewal date — so the question 'what are we covered for' has an answer.*

Where they overlap, and where you pay twice

Buying an AMC on equipment still inside its manufacturer warranty is common and often wasteful. For the overlapping period you may be paying for labour you would have received free.

It isn't always wrong — an AMC usually adds scheduled servicing that the warranty doesn't include, and that may be the thing you actually want. But it should be a decision rather than an accident, and it can only be a decision if warranty expiry is recorded somewhere visible.

What to record against every covered asset

• Kind — manufacturer, extended, AMC or CMC. Without this, none of the other fields mean anything.
• Provider, and the vendor record behind them, so spend by provider is a report rather than an archaeology exercise.
• Policy or contract number — the thing you are asked for first on any claim call.
• Claim contact — a phone number, email or portal. Finding this is where claim time goes.
• Cost of cover, so total cost of ownership includes what you paid to be protected.
• Start and expiry dates, with a reminder before expiry rather than after.
• Terms — what is and is not covered, in the provider's words, for the argument later.

Deciding between AMC and CMC, with numbers

This is an expected-cost calculation and it's simpler than it looks — the hard part is having the data, which is itself an argument for recording actual repair costs against assets.

1. Take last year's parts spend on the equipment in question. Parts only, not labour.
2. Take the price difference between the AMC and CMC quotes.
3. If parts spend exceeded the difference, the CMC would have been cheaper. If not, the AMC was.
4. Then adjust for variance: if a single component failure could exceed the difference several times over, the CMC is also buying you predictability, which has value beyond the average.

Reading the exclusions, briefly

Nobody reads these until a claim is refused. Four exclusions cause most of the refusals:

• Consumables and wear parts — belts, filters, batteries. Frequently excluded even under a comprehensive contract.
• Accidental damage and misuse — almost always excluded, and 'misuse' is defined by the provider.
• Unauthorised repair — opening the item yourself commonly voids everything, including future claims.
• Response times — often a target rather than a commitment, unless the contract says otherwise explicitly.

Record the exclusions on the asset alongside the policy number. The moment you need them is the moment nobody can find the contract.

Renewals are where cover quietly lapses

Annual contracts expire annually, which sounds obvious and is routinely missed. The failure is usually organisational: the person who arranged the contract has moved on, the renewal notice went to an inbox nobody reads, and the lapse is discovered when a claim is refused.

Two things prevent it. A reminder that fires before expiry rather than on it, and a renewal chain on the record so a renewed contract keeps the history of the one it replaced — which is what lets you see that cover has been continuous rather than assuming it.