What an Assumption in a Quote Is Doing

Why this matters

An exclusion carves something out. An assumption does the opposite: it pulls an unknown into the quote, states it as though it were known, and invites the only person who can actually check it to correct you. That is its whole job. An assumption is not primarily a defence for later. It is a cheap request for information, aimed at the customer, at the one moment when correcting the quote costs a phone call instead of a day.

Shops that treat assumptions as legal armour write them defensively and get little back. Shops that treat them as questions in declarative form get their quotes corrected before the truck rolls, which is where the money is.

The mechanism

You cannot see inside the wall. You can price the job three ways:

• Price the good case and hope. You carry the unknown, and you find out when it costs the most to find out.
• Price the bad case. The customer carries it in the form of a higher number, and you lose bids to shops that did not.
• State the good case as an assumption. The unknown is now visible, in writing, to the person who has lived in the building for eleven years and knows the answer.

The third option is the only one that can actually resolve the unknown before work starts, because it is the only one that puts the question in front of someone with information you do not have. Customers correct assumptions surprisingly often, and they almost never correct a price.

What separates an assumption from an exclusion

They are frequently confused, and mixing them produces clauses that do neither job.

An assumption that is really an exclusion in disguise ("we assume no additional work will be required") is the worst of both. It states nothing checkable and carves out nothing specific.

What makes an assumption answerable

The customer has to be able to answer it. That rules out most of what gets written.

• Written in the customer's vocabulary, not yours. "Assumes the existing service is adequate" is unanswerable by a homeowner. "Assumes nothing has been added to the electrical service since the house was built, such as a shop, a pool, or a second heating system" is answerable, and the answer is often yes, there is a shop.
• About history and access, not about engineering. Customers know what was done to their building and where things are. They do not know sizing, capacity, or condition inside a chase. Aim assumptions at what they actually know.
• One fact per line. Compound assumptions get a compound answer, which is no answer.
• Attached to a consequence. "If any of these turn out differently, we will re-quote that portion before starting it" is one sentence and it converts the whole block from a disclaimer into a process.

Worked example: six months of corrected quotes

A shop added a short assumptions block to one quote template. Not a legal paragraph: three to five plain-language lines, printed above the signature, with the re-quote sentence at the bottom.

Over six months, 48 quotes went out on that template.

• 7 came back with an assumption corrected by the customer before acceptance. That is 7 of 48, about 15 percent.
• Of those 7, the shop judged that 5 would otherwise have surfaced mid-job, because the correction was about something concealed or about prior work the estimator could not have seen from the walk-through. The other 2 concerned things that would have surfaced during the walk on the first morning instead, and one of those 2 is the case below.
• The 5 that would have surfaced mid-job carried re-quotes averaging 4.2 additional hours each, so 21.0 hours of work got priced and sold that would otherwise have been discovered with the job open.

What matters is not the 21.0 hours. It is that all 21.0 were negotiated while the customer still had every option available, including declining. All 5 accepted, which is the number worth thinking about: when the extra work is presented before anything is disturbed, with the reason visible in the assumption the customer themselves corrected, the acceptance rate is high because the customer feels like a participant rather than a captive.

Two of the 7 corrections came from the same line, the one about additions to the building since it was built. That line alone accounted for 2 of the 7 corrections, and it survived the next template revision unchanged for that reason.

One of the 7 corrections was itself wrong, and that case is worth its own paragraph. The customer corrected an assumption about the electrical service by stating it had been upgraded when the addition was built. The estimator re-priced on that correction, dropping a 3.0 hour item. On site, the service was original. The shop absorbed the 3.0 hours and did not bill for them, because arguing about it would have cost more than the hours.

That outcome is not an argument against assumptions. It is the reason the assumption is written as a request rather than as a warranty. A customer's correction is information, not a guarantee, and the right response to a load-bearing correction is to go and look at the thing before pricing on it. In this case the correction dropped an item worth 3.0 hours from the quote, which crossed the shop's own line for verification and should have triggered a second visit.

Which gives a usable rule with its unit stated: verify any customer correction that changes the price of a single line by more than about 2.0 hours, per quote, before it goes out. Below that, price on their answer and accept the occasional miss, because the verification visit costs more than the exposure. Above it, go and look. The threshold is a starting point, tuned to what a verification visit costs you.

One more figure from the same period, and it is the honest one: 41 of the 48 quotes came back with the assumptions uncorrected. Of those 41, three still hit a mid-job surprise that no assumption had named. The block is not a net. It catches the unknowns you were smart enough to name, which is a real but partial category, and the residual is what contingency exists to cover. See related: The Contingency Line and How to Size It.

What the customer's silence means

Here is the part shops get wrong. When the customer does not correct an assumption, you have not obtained a warranty from them. You have obtained something weaker and still useful: evidence that the assumption was disclosed and unchallenged before they accepted.

Whether that shifts any legal responsibility depends on your contract terms and on state law, and it differs for consumer and commercial customers. Do not build your pricing on the belief that an uncorrected assumption transfers the risk. Build it on the belief that a corrected assumption saves you the job. The first is a legal question for your own attorney; the second is an operational fact you can bank.

There is one exception worth naming. If the customer affirmatively confirms an assumption in writing, in their own words, that is materially stronger evidence than silence. When an assumption is genuinely load-bearing, ask for the confirmation rather than relying on the absence of an objection.

Where assumptions go stale

An assumption block that never changes stops describing your risk. Two decay patterns:

The block that grew. Every bad job adds a line. After two years the block has fourteen lines, the customer reads none of them, and the correction rate falls to nothing. The block is a communication instrument, and a communication instrument that nobody reads has failed regardless of how complete it is. Cap it at about five lines per quote and rotate lines in and out based on which ones actually get corrected.

The line nobody has corrected in two years. Either that condition is genuinely universal in your market, in which case it is not an unknown and does not need a line, or it is written in language the customer cannot evaluate. Both mean the line comes out. Track corrections per line the way you would track which upsell actually closes.

Where the block goes on the page

Placement decides whether an assumption ever gets read, and most shops put it in the worst available spot.

On the quote itself, above the signature line, in the same type size as the scope. Not in a terms document, not on the back, not in a smaller font, not behind a link. An assumption exists to be read by the customer before they accept; anything that reduces the chance of that reduces the value of the instrument to nothing, whatever it does for you legally.

Read out loud at acceptance if the quote is presented in person. Thirty seconds, in the customer's kitchen, going through three or four lines and asking after each one whether that sounds right. This is where corrections actually come from. A block that is emailed gets skimmed; a block that is read aloud gets answered, and the answers are the product.

Repeated on the work order the crew carries. The technician is the one who will meet the condition, and a technician who knows the quote assumed the service was original will flag it in the first ten minutes instead of the sixth hour.

What changes the answer

Commercial bid work with a stated response format. Some buyers treat conditional language as a qualification and score it against you, or reject the bid outright. There, assumptions have to be taken as formal exceptions in whatever the bid instructions call for, at bid time, in their format. Most solicitations treat an exception raised after award as ineffective, and the solicitation's own instructions are what decide it. Read them before you assume a post-award exception buys you anything.

Work where you can just go and look. If the unknown is behind an access panel you could open on the estimating visit, an assumption is the lazy answer. Spend the ten minutes. Assumptions are for what you genuinely cannot see without doing destructive work or without information only the owner holds.

How to verify your assumptions are earning their place

For one quarter, mark every quote where an assumption was corrected by the customer and note which line did it. At the end, you will have three groups: lines that get corrected regularly, lines that never do, and surprises that no line named. Keep the first, cut the second, and write a new line for the third if it happened more than once. That is the entire maintenance loop, and it takes an hour a quarter. A block maintained this way stays around five lines forever and keeps working; a block that only ever grows stops working in about two years.

References

• Whether disclosed assumptions affect allocation of responsibility depends on your contract terms and on state law, and differs for consumer and commercial customers; have your own attorney review load-bearing language
• See related: The Conditions Clause: Protect the Quote; How to Write an Exclusion That Holds Up Later; The Contingency Line and How to Size It