Legal description glossary

Lot and block identifies a parcel through its recorded subdivision plat

The written description can be short because the recorded plat supplies the boundary detail, streets, easements, and lot layout behind it.

Last updated: August 1, 2026

Lot and block: definition first

Direct answer: Lot and block, also called the recorded-plat method, is a legal-description system that identifies a parcel by its lot number, block number when used, named subdivision, and recording jurisdiction or plat reference. The recorded subdivision plat contains the map and dimensions that give those identifiers geographic meaning. A complete description must point to the correct recorded plat rather than rely only on a mailing address.

Why it is on the exam: PSI lists lot and block, or recorded plat, as one of the three legal-description methods in Property Ownership. Illinois's Plat Act governs the surveying, acknowledgment, approval, and recording framework for land divided into subdivisions, subject to its provisions and exceptions.

Also called

Recorded-plat method

Parcel identifier

Lot and sometimes block

Map source

Recorded subdivision plat

Common setting

Platted subdivision

Do not substitute an address for the recorded legal identity

Decision point	Lot-and-block description	Street address or parcel number
Primary purpose	Legally identify the platted parcel	Address: delivery and location. Parcel number: assessment administration
Source	Recorded subdivision plat and recording reference	Local addressing or assessor system
Boundary detail	Supplied by the referenced plat	Not ordinarily supplied by the number alone
Change risk	Remains tied to the recorded plat unless legally replatted	Addressing and assessor identifiers can change

Read from the smallest identifier to the recording source

A description might identify Lot 8 in Block 3 of a named subdivision according to a plat recorded in a particular county document or plat book. Lot and block locate the parcel within the drawing. The subdivision name and recording information locate the correct drawing within the public record.

Not every subdivision uses blocks, so the absence of a block number does not automatically make the method invalid. The essential task is to match the description to the plat's own labeling and the correct recording reference.

Confirm the exact lot number.
Include the block when the plat uses one.
Match the full subdivision name and any phase or unit.
Verify the county and recording reference.

Open the plat to see what the short description omits

The plat can show dimensions, streets, alleys, easements, common areas, monuments, dedications, building lines, and notes. The words Lot 8 do not reproduce that information. They incorporate the mapped parcel by reference.

A buyer should not infer that every visible fence or driveway matches the platted boundary. A current survey can compare occupation on the ground with the record plat and reveal encroachments, overlaps, or unrecorded conditions.

Distinguish a subdivision plat from the rectangular survey grid

A developer or owner uses a subdivision plat to divide a tract into lots, blocks, streets, and other areas under the governing process. The underlying tract may itself have been described using metes and bounds or the rectangular survey system before it was platted.

Once the lot is validly platted and recorded, the lot-and-block reference can identify the new parcel without repeating the outer tract's full boundary walk. This is why more than one description system can appear in the title history without identifying competing land.

Two subdivisions share the same lot number

Question: A deed says only 'Lot 12' in a county where several recorded subdivisions contain a Lot 12. Does the description reliably identify one parcel?

Best answer: No. The description needs the subdivision and recording context required to identify the intended recorded plat and lot.

Why: A lot number is unique only within its plat context. The full subdivision name, block if applicable, jurisdiction, and recording reference distinguish one Lot 12 from another.

Lock in the distinction

Exam trap

Do not choose lot and block merely because the property is inside a city. Choose it when the legal description refers to a recorded plat, lot, subdivision, and related identifiers.

Memory cue

Lot locates inside the map; subdivision and recording reference locate the map.

Quick questions

What is another name for lot and block?

The recorded-plat method, because the lot identifier depends on a subdivision plat recorded in the public records.

Does every lot-and-block description need a block number?

No. Some plats number lots without using blocks. Follow the identifiers shown on the recorded plat.

Is a parcel identification number a legal description?

An assessor's parcel number is useful for tax administration and searching, but it ordinarily does not replace the controlling recorded legal description.

Where are the lot dimensions found?

They are generally shown on or derived from the referenced recorded plat, subject to survey evidence and later recorded changes.

Primary sources and review status

Checked through August 1, 2026. This definition is an exam-prep explanation, not a substitute for current law or advice about a live dispute. The current official source controls if the outline or Illinois rule changes.