Capacity to Contract: The Signs and What to Do

Why this matters

Every signed estimate assumes the person signing understood what they agreed to. Most of the time that is true. Sometimes it plainly is not: the customer who asks three times in ten minutes what the new unit is for, who signs whatever is put in front of them, who cannot say back what the job is. A signature from that person protects nobody. The family can challenge it, the shop can end up unwinding a finished install, and in the worst version a regulator or a reporter reads it as a shop that sells to people who cannot say no. This card owns the idea of capacity for the rest of the library: what it is, the signs a tech can actually see, how to slow down without insulting anyone, and when to bring in someone else.

What capacity means, in plain terms

Capacity (lawyers say "contractual capacity" or "mental capacity") is the ability to understand the nature and consequences of an agreement at the time you make it. In most states the working test has four parts, and a person needs all four for a given decision:

1. Understand the information: what the work is, what it costs, what happens if they say no.
2. Appreciate that it applies to them and their house.
3. Reason about it: compare the options, weigh the cost against the problem.
4. Communicate a choice, and keep the same choice when asked again a few minutes later.

Three features make capacity harder than it sounds.

It is decision-specific. A person can have capacity to agree to a filter change and lack it for a whole-house system replacement. The bigger, more complex and more expensive the decision, the more understanding it requires.

It fluctuates. Dementia often worsens late in the day (care staff call it sundowning). A urinary tract infection, dehydration, a new medication or a fall can cause delirium, a sudden, usually temporary confusion, in a person who was sharp last week. The customer who seems lost at 6 pm may be fine at 10 am.

It is presumed. An adult is assumed to have capacity unless something shows otherwise. Age is not that something. An 88-year-old who asks careful questions and drives a hard bargain has more capacity for the decision than a tired 45-year-old who signs without reading.

The signs a tech can see

None of these alone proves anything. Two or three together, on a decision of any size, are the cue to slow down.

The two that matter most are cannot say it back and repeating the same question, because they test understanding directly. The others are context.

The move: slow down and test understanding

The tool is a teach-back: you explain, then ask the customer to explain it back in their own words. Nurses use it with discharge instructions because it tests understanding without asking anyone to prove they are competent, which is how it has to feel.

Done well, it sounds like this in prose: after walking through the estimate, the tech says, "I've thrown a lot at you. Just so I know I explained it right, can you tell me what you'd be getting and roughly what it costs?" The burden sits on the tech's explanation, not on the customer's mind.

If the answer is close, fine: correct the small miss and proceed. If it is far off, explain again more simply, one option at a time, in writing. If the second teach-back still misses, stop selling.

For conversational pace and how to speak with an older or anxious customer, see related: Speaking With an Elderly or Anxious Customer. This card is about the decision, not the delivery.

Bringing someone else in, with permission

When the teach-back fails twice, the next move is another person, and the customer stays in charge of who.

• Ask, do not announce. "This is a big decision. Is there someone you'd like to go over it with before you decide? I'm happy to come back or talk to them on the phone." Many customers welcome it.
• Their choice of person, not yours. Do not ring the emergency contact on the account without permission. A listed contact is not an authorized decision-maker.
• If someone holds authority, a financial power of attorney or a court-appointed guardian, the decision may be theirs to make. See related: Working With a Power of Attorney or Guardian.
• If the customer refuses to involve anyone and still cannot show understanding, you do not have to sell. Offer the safety-only repair if one is needed, leave a written estimate, and go.

Why the signature does not protect you

The instinct is that a signed contract is armor. With a customer who lacked capacity, it is closer to evidence.

In most states a contract made by someone who lacked capacity at the time is voidable: the person, or later their guardian or estate, can cancel it. Where a court has already declared the person incompetent and appointed a guardian, a contract they sign alone is often treated as void, meaning it never had effect. Courts look at whether the other party knew or should have known. A tech's own notes saying "customer repeated questions, could not explain job" are the strongest possible proof that the shop should have known. That is a legal question for your own attorney if it arises, and this is not legal advice; the operational fact you can bank is that a signature from someone who could not say back what they signed is the weakest document in your file.

The exposure is wider than one contract. Many states have elder-abuse statutes with financial-exploitation provisions that can reach a business, and some add enhanced penalties under consumer-protection law for unfair practices aimed at older buyers (California's elder financial abuse statute and the enhanced civil penalties in several state consumer-protection acts are examples). Whether either applies turns on facts, intent and state law, but neither is a fight a shop wins by producing the signature.

Worked example: a water heater, and then a repipe

A plumber goes out at 4:30 pm on a leaking 40-gallon gas water heater. The customer, Helen, is 88 and lives alone. The tank is leaking at the bottom seam, so replacement is the honest answer, about a half day of work. The plumber also notices galvanized supply piping with heavy corrosion at the fittings and prices a whole-house repipe at roughly six times the water heater.

The first explanation. The plumber walks through both: the water heater is needed now; the repipe is recommended within a couple of years. Helen nods, says "Whatever you think is best, dear", and reaches for the tablet.

Signs so far: agrees to everything. One sign, on a large decision. The plumber does a teach-back: "Just so I know I made sense, what are we doing today?" Helen: "You're fixing the leak under the sink." Wrong job.

The second explanation. The plumber separates the two decisions, writes the water heater on one sheet and the repipe on another, and explains only the water heater: the tank is rusted through, it will not stop leaking, a new one is half a day, here is the price. Teach-back: "So what's wrong with it?" Helen: "The tank's rusted and it'll keep leaking, so it needs to be a new one." Close enough. She asks how long she will be without hot water, which is reasoning about consequences. For this decision, the four parts are present.

The repipe. The plumber tries the same thing. Helen asks twice in five minutes whether the repipe is "the same as the tank", and when asked to say it back answers "it's for the leak". Two misses, a large, non-urgent decision, late afternoon.

The call. The plumber does the water heater, which Helen understands, which stops active water damage and which any reasonable person would choose. On the repipe: "This one isn't urgent. Would you like me to leave the estimate and talk it over with someone? I can come back any morning." Helen says her niece usually helps with "the big things". With Helen's permission the plumber calls the niece from the driveway, explains that the repipe is a recommendation with no deadline, and leaves the written estimate. The job note records the teach-back results in fact form: "Second teach-back on water heater correct. Repipe: customer twice described it as the sink leak; not sold, estimate left, niece called with customer's permission."

What changes the answer. Had the water heater teach-back also failed, the plumber would shut off the gas and water to the tank, which removes the active hazard and the leak, and come back with the niece rather than install on a signature Helen could not explain. Had Helen's leak been a gas leak, the safety work comes first regardless of capacity: make the appliance safe, sell nothing beyond what makes it safe. And had the niece held a financial power of attorney, the repipe decision could be hers, though Helen still stays in the conversation.

What not to do

• Do not refuse to deal with older customers as a group. Presumed capacity cuts both ways; declining to quote because someone is old is its own problem.
• Do not test memory with quiz questions ("who's the president?"). That is a clinician's tool, it humiliates people, and it is not your call.
• Do not let the person who is present decide for someone who has capacity. A daughter who wants the cheaper option does not get to overrule a mother who understands and wants the better one.

References

• American Bar Association Commission on Law and Aging and American Psychological Association, "Assessment of Older Adults with Diminished Capacity: A Handbook for Lawyers" (the four-part decisional test)
• Agency for Healthcare Research and Quality, Health Literacy Universal Precautions Toolkit (teach-back method)
• See related: Working With a Power of Attorney or Guardian
• See related: Elder Financial Exploitation: The Signs a Tech Sees
• See related: What a Tech Can and Cannot Do About a Welfare Concern