Most people think a Cook County property tax appeal is one thing you do at one place. It isn't. It runs through **two separate offices, in sequence, each with its own filing window and its own rules about who is even allowed to file.** Miss that, and you can either run out of clock or walk into the one office where the way you hold title decides whether you can represent yourself at all.
This is the map. Read it before you file anything.
Quick Answer
A Cook County appeal runs through two separate offices in sequence — first the Assessor, then the Board of Review — each with its own filing window and its own rules. The catch: who is allowed to self-file changes between them.
At the Assessor, anyone can self-file, including LLCs. At the Board of Review, an individual can still self-file for property in their own name, but a corporation, LLC, trust, or condo association must use a licensed attorney.
The Two Offices Are Not the Same Office
When people say "appeal my Cook County taxes," they are usually compressing two different proceedings into one phrase.
**First office — the Cook County Assessor.** This is where your assessment originates, and it is the first place you can challenge it. The Assessor can re-open and lower your value directly. Each township gets a roughly 30-day appeal window that opens when that township's reassessment notices mail; the last date to file is printed on the notice, and there is no extension (Cook County Assessor assessment calendar).
**Second office — the Cook County Board of Review.** This is a **separate, quasi-judicial body** — not a department of the Assessor. After the Assessor finishes a township and certifies its values, the Board opens its own appeal window on the same property. The Board's dates are independent of the Assessor's and come later in the cycle (Cook County Board of Review).
So a single parcel can be appealed twice in one year, at two offices, on two different calendars. They do not share a deadline, they do not share a filing system, and — the part that surprises owners — they do not share the same rule about who may file.
The Representation Rule Flips Between Them
This is the load-bearing difference, and it is the reason this article exists.
**At the Assessor, anyone can self-file — including entities.** The Assessor's official rules are explicit: *"No party is required to be represented by an attorney or other agent when filing an appeal at the CCAO, including parties that are business organizations such as LLCs"* (Cook County Assessor, Official Appeal Rules, Rule 5). A homeowner, an LLC, a trust — all can file at the Assessor on their own.
**At the Board of Review, the rule changes — and it depends on how you hold title.** The Board's official rules state: *"All parties, other than pro se taxpayers, must be represented before the Board by an attorney. Other taxpayers, including but not limited to entities such as corporations, LLCs, condominium associations and the like, must be represented by an attorney"* (Cook County Board of Review, Official Rules, Rule 1).
In plain terms, at the Board of Review:
- **An individual** holding property **in their own name** can still appear **pro se** — file for themselves, no attorney required.
- **A corporation, LLC, or condominium association** — and, by the same logic, any other non-individual owner such as a partnership or trust — **cannot** self-represent. It **must** use a **licensed attorney.** A non-attorney — including the owner or a manager of the LLC — may not represent the entity before the Board.
Note carefully what this is *not*. It is **not** a blanket "you need a lawyer to appeal your taxes." An individual can self-file all the way through. The attorney requirement is **specific**: it applies **only at the Board of Review, and only to entities.** If the deed says "John and Mary Smith," they can do the whole thing themselves. If the deed says "123 Main Street LLC," the LLC needs an attorney the moment it reaches the Board — even though that same LLC could have filed at the Assessor on its own.
Why the Order and the Windows Matter
Because the offices run in sequence, the practical workflow looks like this:
- **Watch your township's Assessor window.** It opens on a staggered, per-township schedule and runs about 30 days. There is no countywide deadline and no extension.
- **If you have a case, file at the Assessor first.** Anyone can. The Assessor may lower the value without you ever reaching the second office.
- **If you are not satisfied — or want a second venue — the Board of Review opens later** on that same property, on its own separate window after the Assessor certifies.
- **At the Board, check how you hold title.** Individual in your own name: you can self-file. Entity (LLC, corp, trust, condo association): the Board's rules require a licensed attorney.
In 2026, the South and West suburban townships are in reassessment, so owners there are getting fresh values and fresh windows at both offices this cycle.
The thing that quietly costs owners is treating this as one deadline and one set of rules. It is two of each, and the second office is where the entity-attorney requirement lives.
How Heavily Used Is the Attorney Path?
The Board's record gives a sense of how the market actually behaves. We aggregate the public Board of Review decision dataset — **6,735,334 appeal decisions across tax years 2010–2025** — and roughly **86% of those decisions were attorney-represented.** That is not a rule that 86% of owners *must* use an attorney; individuals are free to self-file. It reflects who is in front of the Board: a large share of Board-level appeals involve entity-titled or higher-value property, exactly the segment the rule channels toward counsel. It is context, not a prediction about your parcel.
Where Censum Fits
Censum is an independent property-tax intelligence and filing-rails company — **not** the county, **not** a government office, and **not** a law firm. It does not represent you before the Board and does not provide legal advice. What it does is the part before the representation question:
- **Look up your PIN or address** and see the county's record on your parcel, a valuation signal worth reviewing, and where the parcel sits in its township's Assessor and Board windows.
- **For an individual self-filing,** that is often all you need to decide and act inside the window.
- **For an entity** — an LLC, trust, or condo association — Censum can **prepare** the appeal and get it **ready for the licensed attorney** the Board of Review requires, so the file is built and the deadlines are mapped before counsel steps in. Censum prepares; the attorney represents — engaged and paid directly for the legal work, and Censum never takes a share of that fee. (Censum's filing intake is currently prepare-only.)
The signal is research to help you decide which parcels are worth a closer look — not a guarantee of any reduction. Assessed value is the county's valuation, not your tax savings, and nothing here promises an outcome.
FAQ
Is the Board of Review the same as the Assessor?
No. They are two separate offices. The Assessor sets your value and hears the first appeal; the Board of Review is an independent, quasi-judicial body that hears a second appeal on the same property after the Assessor certifies. Each has its own filing window.
Do I need a lawyer to appeal my Cook County property taxes?
Not necessarily. At the Assessor, no one needs an attorney — including LLCs and corporations. At the Board of Review, an individual can still self-file for property held in their own name. The attorney requirement applies only to entities — corporations, LLCs, trusts, and condo associations — and only at the Board of Review.
My property is owned by an LLC. Can I file the appeal myself?
At the Assessor, yes — the rules let business organizations like LLCs file without an attorney. At the Board of Review, no: the Board's Rule 1 requires corporations, LLCs, trusts, and similar entities to be represented by a licensed attorney. A non-attorney, including the LLC's owner or manager, may not represent the entity before the Board.
Can I appeal at both offices in the same year?
Yes. Because they run in sequence, the same parcel can be appealed first at the Assessor and then at the Board of Review in the same tax year — on two separate windows. They do not share a deadline.
When are the windows?
There is no single Cook County deadline. The Assessor opens each township for about 30 days, on a staggered schedule, with the last-file date printed on the notice and no extension. The Board of Review runs its own, later windows after the Assessor certifies. Look up your PIN to see where your specific parcel sits.
Does Censum represent me before the Board?
No. Censum is an independent intelligence and filing-rails vendor — the flat-fee software, not a law firm and not your representative. Where the Board requires an attorney, Censum prepares the appeal and gets it ready for the licensed attorney, who is engaged and paid directly for the legal work; Censum never takes a share of that fee and does not provide legal representation or legal advice.
Next Step
Before you decide where to file — or whether your entity needs counsel — find out where your parcel actually sits. Look up your PIN or address to see the county's record, the valuation signal, and both the Assessor and Board of Review windows for your property. Censum is independent and is not affiliated with Cook County.