Most guidance on hiring a contractor is a list of reassuring qualities — experienced, reputable, professional. None of those is checkable, which is why the advice feels useless the moment you are holding two business cards. A better question is narrower: of everything a company tells you, which parts can you independently confirm before you commit money?
Who this helps
A homeowner deciding which company to invite to quote, or which of several to actually sign with.
When to read it
Read this before the first call if you can, and certainly before signing. The checks that matter most are the ones that get awkward to raise late.
What you can decide afterwards
Which companies survive the checks you can actually perform, and what has to be in writing before the remaining choice is safe to make.
Quick answer
Sort what you are told into four piles: what you can confirm yourself from a public record, what only counts if it is written into the proposal, what nobody can settle until they stand at your property, and what you genuinely cannot know until the work is underway. Most hiring regret comes from treating something in the third or fourth pile as though it were in the first. The checks worth doing are unglamorous — licence status against the state's own register, an insurance certificate sent by the insurer, and who physically performs the electrical work.
What this chapter can help you determine
Which claims about a company you can verify yourself, which have to be captured in the contract to mean anything, and which are genuinely unknowable until work begins.
Sorting a company's claims by whether they are verifiable, contractual, or neither.
Which public records exist and what they do and do not prove.
How subcontracting changes who you are actually hiring.
The contract terms that determine what happens when something goes wrong.
Warning signs that are worth acting on, and ones that are merely irritating.
Sort everything you are told into these four piles
Pile one: you can confirm this yourself, today
Facts held in a public register or issued by a third party. You do not need the contractor's cooperation to check them, and a company's reaction to being checked is itself informative.
This points here when:
A licence or registration number appears on the proposal, the vehicle or the website.
The company names the legal entity it trades as.
Insurance is claimed, and a certificate can be sent directly by the insurer or broker.
If this is the wrong call: Discovering after a failed inspection that the credential you assumed existed was expired, held by a different entity, or never held at all — at which point the work is in your house and the leverage is gone.
Pile two: only the written proposal makes this real
Commitments that are perfectly sincere when spoken and unenforceable when disputed. Scope, exclusions, who pulls the permit, how changes are priced, what completion includes.
This points here when:
Something important was agreed in conversation and does not appear in the document.
The proposal says work is by others or by owner without naming who.
A schedule, an allowance or a warranty term was described verbally.
If this is the wrong call: A disagreement months later in which both parties remember the conversation differently and only the document counts.
Pile three: nobody can settle this remotely
Determinations that require someone at the property with instruments: electrical service capacity, fuel supply adequacy, placement against clearances, and what the existing panel will actually support.
This points here when:
A company quotes a firm price without having visited.
Two proposals disagree about capacity or transfer scope.
Fuel supply has not been confirmed with the gas supplier or by measurement.
If this is the wrong call: A price that moves substantially once someone finally looks, usually as a change order after the equipment is ordered.
Pile four: you cannot know this in advance
Workmanship quality, how the company behaves under pressure, and whether they return calls after final payment. No amount of research converts this into a fact before the work starts.
This points here when:
You are weighing companies that all pass the first three piles.
You are tempted to treat online sentiment as evidence of how your job will go.
If this is the wrong call: Over-researching the unknowable while skipping the licence check that takes four minutes — spending effort where it cannot help and withholding it where it can.
What you probably already know
Roughly what you want installed.
Which companies serve your area.
What each company told you about itself.
Whether you found them easy to talk to.
What is commonly still unknown at this point
Whether the licence number belongs to the entity on the proposal, or to a person no longer with the company.
Who physically performs the electrical work, and whether that firm has been evaluated at all.
Whether the manufacturer's warranty requires an installer credential, and whether this company holds it.
What the proposal excludes, since exclusions are usually stated once and briefly.
How a change in scope gets priced once work has started.
Information to gather
The exact legal entity name and any licence or registration number, as written on the proposal rather than as spoken.
A certificate of insurance sent directly by the insurer or broker, not forwarded by the contractor.
The name of the firm performing the electrical work, if it is not the company you are hiring.
The manufacturer's own warranty document for the equipment proposed, obtained from the manufacturer.
Written confirmation of who applies for permits and who attends inspection.
The change-order procedure and the payment schedule, both in writing.
Questions worth asking, and what a good answer sounds like
What legal entity would I be contracting with, and what is its licence or registration number?
Who performs the electrical work — your own employees, or a subcontractor? If a subcontractor, which firm?
Will you apply for the permit, and will you attend the inspection?
Does the manufacturer's warranty require any installer credential for this equipment, and do you hold it?
What does this proposal exclude that a finished, working installation would need?
How is a change in scope priced and approved once work has started?
What does the payment schedule tie each stage to?
What will I have at completion — documentation, start-up, warranty registration, site restoration?
When this does not apply
The work is warranty service on an existing unit, where the manufacturer usually dictates who may perform it.
There is an active hazard. Stop and call the utility or emergency services rather than shopping.
You have not yet decided what to install — the specification shapes who is even a candidate.
What would change the decision
A licence lookup returns a different legal name than the one on the proposal.
The electrical work turns out to be subcontracted to a company you have not evaluated.
The insurance certificate arrives from the contractor rather than from the insurer.
The manufacturer's warranty terms require an installer credential the company does not hold.
What an inspection can confirm
Whether the existing electrical service can carry the proposed system.
Whether the fuel supply is adequate at the required flow, not merely present.
Whether a candidate location meets clearance and exhaust requirements at this specific property.
What the installation actually requires, as opposed to what a phone conversation assumed.
Who is responsible for what
Who decides, who performs, and who confirms — the division that determines where you are exposed if a step is skipped.
Approval responsibilities, by item.
Item
Decided by
Performed by
Confirmed by
What you should hold
Licence and registration standing
The licensing authority
The contractor, by holding it
You, against the authority's own register
The lookup result and the date you checked it
Liability and compensation insurance
The insurer
The contractor, by carrying it
The insurer or broker, issuing the certificate directly
The certificate as received from the insurer
Scope of work and exclusions
You and the contractor together
The contractor, in the written proposal
You, by reading the exclusions in full
The signed proposal and every written amendment
Permit application and inspection
The authority having jurisdiction
Whoever the contract names
The inspection record
The permit number and the closed inspection
Warranty registration
The manufacturer's terms
Whoever the contract names
The manufacturer, on registration
Written confirmation the unit is registered to your address
What requires a qualified professional
Every technical determination in a proposal belongs to a qualified professional. This chapter helps you evaluate evidence about a company; it does not help you evaluate whether their engineering is right.
Electrical work, transfer-switch work and fuel connections are performed by qualified trades under permit and inspection. Nothing here is an invitation to assess or perform that work yourself.
Licence classes, permit requirements and who may legally perform which task vary by jurisdiction and change over time. Confirm the current rule with the authority having jurisdiction rather than with any website, including this one.
What this page cannot determine
Whether any particular company is competent or honest.
Which installer you should hire.
What licence class applies in your jurisdiction.
Whether a price is reasonable for your market.
Deliberately out of scope here:
Assessing, ranking or recommending any named company.
Whether a quoted price is fair for a market.
Whether a proposed technical approach is correct.
Licence requirements for any specific jurisdiction, which vary and change.
Common questions
Is a manufacturer dealer badge the same as a licence?
No. A dealer or authorised-installer badge is a commercial relationship with a manufacturer. A licence is a credential issued by a public authority. A company can hold either without the other, and the badge tells you nothing about licence standing — check the register separately.
How much should online reviews count?
Treat them as weak evidence about consistency and no evidence at all about licensing, insurance or scope. Review volume is easy to influence and impossible to audit from the outside. A four-minute licence lookup tells you more than an hour of reading reviews.
Is it rude to ask for an insurance certificate?
It is routine, and it should be sent by the insurer or broker rather than forwarded by the contractor. A company that installs generators for a living has been asked before. Reluctance to have a certificate sent directly is itself an answer.
What if the electrical work is subcontracted?
That is common and not a problem by itself, but it changes who you are relying on. Ask which firm performs it, and apply the same licence and insurance checks to them. The contract is still with the company you hire, so the responsibility for their subcontractor should be written into it.
Should I pick the cheapest quote if the scopes match?
If the scopes genuinely match after a careful comparison, and both companies survive the verification checks, price is a legitimate deciding factor. The mistake is reaching that conclusion before doing either piece of work.
Bottom line
You are not trying to identify the best installer, which is not knowable in advance. You are trying to eliminate the ones you can rule out with evidence, and to write down enough that the remaining choice is recoverable if it goes wrong.
Safety-sensitive content. Last reviewed .
What to do next
Do this chapter's work on paper: Generator quote decoder. Record, item by item, what each proposal documents — and generate the questions for whatever it does not.
The next decision is Permits, inspections, and who approves a generator installation — Which approval tracks your project touches, who owns each one, and exactly what to confirm with your local authority — none of which can be answered generically, and all of which can be asked precisely.
How to compare generator quotes — Whether the proposals in hand describe the same project, and if not, what has to be answered before any price comparison means anything.
What drives the cost of a standby generator project? — Which scopes this particular project contains, so that a price difference between two proposals can be traced to a scope difference rather than guessed at.
see which areas we route requests to — Once you know what to check, the remaining problem is finding companies to check. This states plainly where we can pass a request on and where we cannot.