PlayInfoBox

Home /Education /How Road-Name Address Systems Work

How Road-Name Address Systems Work

Ever wonder how a building gets its number? Here is how road-name address systems assign order to a street.

What is a road-name address?

A road-name address identifies a location by the name of the road plus a building number, instead of a land-parcel (lot) number. Many countries have adopted this style of addressing as an alternative to older land-registry-based systems, because buildings are arranged in a predictable order along the road, making it easier to find a location in practice.

How roads get classified

Under many road-name systems, roads are grouped into tiers based on width and number of lanes β€” a large multi-lane road might be labeled a "boulevard" or "avenue," a mid-sized road a "street," and a narrower local road a "lane" or "way." The exact width thresholds and terms used vary by country and municipality.

How building numbers are assigned

Numbers typically start at one end of the road and increase toward the other end, often at a fixed distance interval, with one side of the road getting odd numbers and the other side even numbers. A bigger number generally means a building sits farther from the road's starting point β€” though which side gets odd numbers, and how the interval is set, varies by country.

Base numbers and sub-numbers

A road is often divided into evenly spaced 'base numbers,' and a building constructed later, between two existing base numbers, is commonly given a sub-number attached to the nearest base number (for example, '12-1' between 12 and 14). This lets new buildings be added without renumbering the whole street.

Detailed address (unit, floor, etc.)

The building number alone is often not enough for multi-unit buildings such as apartments or office buildings β€” a detailed address adds the specific block, floor, or unit number needed to pinpoint an individual home or office inside the building.

Reference information

Many address formats also allow optional reference information, such as a building name or nearby landmark, to make an address easier to recognize. This is not always mandatory, but it is commonly included to help with mail delivery and visitor navigation.

How it differs from a lot-number address

A lot-number address is based on a parcel of land's registration number, which can end up out of geographic order after land is repeatedly subdivided or merged over time. A road-name address instead follows the physical road, so building numbers tend to run in a more predictable, sequential order β€” one reason many places have shifted toward this system.

When did road-name addressing become common?

Many countries have moved away from land-parcel-based addressing toward road-name and building-number systems over the past few decades, usually running both systems in parallel for a transition period before the road-name system becomes the primary, official address format. The exact timeline and legal status depend on the country.

How building numbers relate to postal codes

A postal code is usually assigned independently by the postal service to group addresses for efficient mail sorting, so its boundaries do not always line up neatly with a single road or its building numbers. When mailing something, it's worth double-checking both the road-name address and the postal code separately, since getting one right doesn't guarantee the other is correct.

Frequently Asked Questions

Can I guess a location just from the building number?

To some extent, yes β€” since building numbers usually increase steadily from the start of the road, a higher number generally means a building sits farther from that starting point. For a precise location, though, a map service is still the most reliable method.

Why do building numbers on the same road sometimes look out of order?

This can happen when a road curves or was extended later, when infill buildings received sub-numbers, or when a single road segment crosses more than one administrative district β€” all of which can make the numbering look less than perfectly sequential at a glance.