Demand Letter for a Brain Injury Claim: What It Has to Establish

A demand letter is a written request that another party pay or do something, sent before a lawsuit. Two very different documents go by that name, and confusing them is costly. One is the short letter you send before filing a small claims case — California’s courts publish a tool that writes it for you. The other is the demand package an injury claimant sends an insurance adjuster: a liability analysis with medical records, billing, and wage documentation attached, and a settlement demand at the end. This page is about the second kind.

Two Documents, One Name

If you are trying to recover money someone owes you — an unpaid invoice, a security deposit, a bad check — the California Courts Self-Help Guide has a Write a Demand Letter tool that produces the letter for you. Asking for the money is a step you have to take before filing a small claims case, and the courts’ own tool is a better starting point than anything a law firm will write about it.

An injury demand is a different exercise. It goes to an insurance adjuster rather than to the person who caused the harm, it is assembled rather than filled in, and it commits you to a position before any negotiation starts. The rest of this page addresses that document.

Key Points

• An injury demand is a package, not a letter. The attachments do most of the work.
• Sending one before treatment concludes is the most common and most expensive mistake.
• A demand letter does not extend any filing deadline. The clock keeps running while you wait for a response.
• Nothing in California law sets a response period. Deadlines in demand letters are conventions.
• Everything in it can be used against you later, including anything you overstated.
• Ignoring a demand has no direct legal consequence for the recipient — the consequence is whatever you do next.

Timing: The Mistake That Costs the Most

A demand fixes a number. If it goes out before the medical picture has stabilized, it fixes a number that does not include care you have not had yet.

Future medical treatment is a category of damages, and it cannot be estimated mid-treatment. Neither can the duration of lost income, or whether a limitation is going to be permanent. A demand sent early anchors the negotiation to an incomplete file, and an insurer that accepts it has bought the whole claim — including the surgery that becomes necessary three months later. Our page on car accident settlements covers what signing a release actually ends.

The countervailing pressure is real: deadlines run, and money is needed now. That tension is a reason to get advice on timing, not a reason to send the demand early.

A Demand Letter Does Not Stop the Clock

This is the second misconception, and it ends claims.

Most California personal injury lawsuits must be filed within two years of the injury under Code of Civil Procedure section 335.1. Sending a demand does not pause that period. Neither does an adjuster telling you the file is under review, or a negotiation that has been going on for months in apparent good faith.

The same applies to the shorter timeline where a public entity may share responsibility, and to the separate requirements that govern a claim on your own uninsured or underinsured motorist coverage. People send a demand, wait for a reply that does not come, and discover the deadline passed while they were being patient.

What Actually Goes in an Injury Demand

The letter is a cover document. What persuades is what is attached and how it is organised.

• The liability analysis. How the incident happened and why the other party is responsible, with the collision or incident report, photographs, and witness information behind it.
• The medical record. Records and reports from every treating provider, in order, with the course of treatment made legible rather than dumped.
• The billing. Itemised, and reconciled — California limits recovery of past medical expenses to the lesser of what was actually paid or incurred and the reasonable value of the services, so billed totals and recoverable figures are frequently different.
• Income loss. Employer documentation rather than an assertion of what was missed.
• Future care, where a provider has said it is anticipated.
• The effect on daily life, evidenced rather than described — the items California recognises are set out on our pain and suffering page.
• The demand itself, and a response period.

What Not to Say

• Anything you cannot document. A demand is a written statement of your position that the defense will hold you to. An overstated symptom or an exaggerated limitation becomes a credibility problem at deposition.
• Anything that misstates the medical record. The adjuster will have the same records.
• Threats you will not carry out. “We will file suit next week” that is followed by six months of silence teaches the adjuster what your demands are worth.
• Anything about criminal consequences. Suggesting that a civil payment will resolve or avoid a criminal matter is territory to stay well clear of.
• Anger. It reads as weakness and it is quoted in claim files.
• Speculation about the other side’s motives in place of evidence about what happened.

The Number

There is no formula. California prescribes no multiplier and no method for valuing non-economic damages, and any figure that circulates as an average is pooling cases that have nothing in common. What a demand should reflect is the documented treatment, the anticipated future care, the income loss, the apportionment of fault the evidence supports, and the coverage actually available.

Two structural points worth knowing. Available insurance often constrains what is realistically collectible regardless of what a claim is worth. And any share of fault attributed to you reduces the recovery proportionally under pure comparative fault, so a demand that ignores an obvious fault argument invites the adjuster to make it for you.

Policy Limits Demands

Where the harm plainly exceeds the at-fault party’s coverage, a demand made within the policy limits carries a significance a general demand does not.

If an insurer refuses a reasonable within-limits demand and the case later produces a judgment above the limits, the person exposed to that excess judgment is the insurer’s own policyholder. The resulting claim belongs to them, not to the injured claimant — a distinction covered on our bad faith insurance page. Setting one of these up correctly is technical work, and doing it badly forfeits the point entirely.

Sending It, and What Happens Next

Send it in a way that produces proof of delivery — certified mail with return receipt is the conventional method, and keeping a complete copy of everything enclosed matters as much as the letter.

Nothing in California law requires a recipient to respond, or sets a period in which they must. Response deadlines in demand letters are conventions, commonly a few weeks. A reasonable period signals seriousness; an unreasonably short one signals inexperience.

What usually follows is a counter well below the demand, a request for additional records, or silence. None of those means the claim has failed. What matters is that the filing deadline continues to run through all of it, and that a claim which cannot be resolved has to be filed before it expires.

If You Are Writing Your Own

People do this successfully, particularly on smaller claims where fault is undisputed. If you are going to:

• Wait until treatment has concluded, or until a provider can say what further care is anticipated.
• Attach the records rather than summarising them.
• Keep the tone factual. Nothing about this document benefits from heat.
• Calendar the filing deadline independently of the negotiation, and treat it as immovable.
• Do not sign anything sent back to you without reading what it releases.

On the generated demand letters that services and chatbots now offer: they can produce a competent-looking document, and a competent-looking document is not the problem. The problem is that a demand’s persuasive force comes from the records behind it and from a judgement about timing and number that a template cannot make. A generated letter also cannot tell you that you are about to send it too early, which is the failure that actually costs money.

Demand Letters on the Peninsula

Our office at 15 North Ellsworth Avenue, Suite 105, San Mateo, CA 94401 handles injury claims across San Mateo County, and civil matters for this area are generally heard in the San Mateo County Superior Court. Demand letters also arise well outside injury work — contract, employment, and property disputes among them — and those run through our California civil litigation practice. More about the office is on our San Mateo page.

How Vaksman Khalfin Can Help

On an injury claim, the work is assembling the record so the demand is supported rather than asserted, advising on when it should go out, framing the number against the coverage that actually exists, and handling what comes back. If the answer is that your claim is straightforward enough to handle yourself, we will say so.

The firm’s personal injury practice is led by Alan D. Khalfin, admitted in California. We handle injury matters on a contingency-fee basis: there is no upfront attorney’s fee, and attorney’s fees are owed only if we recover compensation for you. Case costs are a separate category from attorney’s fees, and how both are handled is set out in the written fee agreement we go through with you before anything is signed. Initial consultations are free.

To speak with a California attorney, call 650-250-0705 or schedule a free consultation. Related reading: what a car accident lawyer does and our California personal injury guides.

Reviewed by Alan D. Khalfin, Partner and Managing Attorney, Vaksman Khalfin, PC (admitted in California). Last reviewed: 09/08/2026