Idaho Plate History at a Glance

SOURCE: Idaho Transportation Department; Idaho State Historical Society.

Idaho’s Early License Plates

Before statewide motor vehicle licensing was established, several Idaho municipalities — including Boise and Lewiston — issued their own local vehicle tags. Idaho formally centralized the system in 1913, enacting its first statewide motor vehicle registration law and issuing state plates manufactured from heavy stamped metal with white figures on a dark blue enamel surface.

Throughout the 1910s and 1920s, Idaho issued new physical plates every year. Each annual issue rotated colors — ranging from black on orange to yellow on dark blue — so law enforcement officers could verify current registration at a glance. Vehicles were assigned plain sequential registration numbers rather than county designations.

These utilitarian early tags fulfilled a purely administrative function, but Idaho would soon pioneer an entirely new role for license plates: turning state bumpers into mobile ambassadors for local agriculture.

When Did Potatoes First Appear on Idaho License Plates?

According to the Idaho State Historical Society, the 1928 plate included the words “Idaho Potatoes” with the vehicle’s registration serial printed directly over a background illustration of an embossed russet potato.

This was a historic turning point in automotive history. Idaho was the very first state in the United States to include an official state promotional slogan on a passenger license plate. While earlier plates had occasionally carried manufacturer emblems or state seals, Idaho was the pioneer in using license plates as an overt advertising medium.

Today Idaho and potatoes are virtually inseparable in American popular culture, but that connection has been appearing on Idaho license plates for nearly a century.

50 Years of Statehood — 1940

Idaho was admitted to the Union as the 43rd state on July 3, 1890.

To celebrate its half-century milestone in 1940, the state issued a special commemorative license plate. According to the Idaho State Historical Society, the 1940 plate featured “1890 Idaho 1940” across the top border and proclaimed “50 Years Statehood” along the bottom edge in crisp embossed block lettering.

Idaho Was a “Vacation Wonderland”

In 1947, Idaho debuted one of its most distinctive and collectible historical plate designs.

According to the Idaho State Historical Society, the 1947 plate featured an embossed illustration of a downhill skier positioned between the county designator and the registration serial, paired with the slogan “Vacation Wonderland.”

Coming immediately after World War II, this design was an early and imaginative example of a Western state utilizing license plates as miniature rolling billboards to promote skiing, outdoor recreation, and scenic mountain tourism to travelers across the country.

“World Famous Potatoes”

In 1948, the potato returned to Idaho plates with an expanded title. According to the Idaho State Historical Society, Idaho’s 1948 and 1949 plates featured an embossed colored potato decal paired with the words “World Famous Potatoes.”

During the following decade, potato slogans briefly alternated with plain issues. In 1953, the singular phrase “World Famous Potato” appeared on plates. In 1956, “World Famous Potato” returned once more.

These variations laid the groundwork for a more concise phrase that would soon define Idaho automotive identity for generations.

The “Famous Potatoes” Era

According to the Idaho State Historical Society, “Famous Potatoes” first appeared on Idaho plates in 1957 and continued as the core state tagline across subsequent decades.

Shortening the wording created a cleaner, punchier bumper slogan that balanced neatly against the registration serial numbers. The tagline survived multiple base redesigns, standardizations, and legislative debates to become one of the most durable and universally recognized license plate taglines in North America.

Why Does the Idaho License Plate Say “Famous Potatoes”?

Idaho plates feature “Famous Potatoes” because russet potatoes are Idaho’s most celebrated agricultural product and the centerpiece of the state’s economic identity.

Southern and eastern Idaho’s volcanic soil, warm sunny summer days, crisp cool mountain nights, and clean irrigation water flowing from the Snake River watershed created perfect conditions for growing baking potatoes. As commercial potato yields boomed in the 1920s, the state legislature and potato growers partnered to promote Idaho spuds across the country.

Idaho was already promoting potatoes directly on its plates by 1928, and “Famous Potatoes” became the permanent standard slogan beginning in 1957.

What Do the Letters and Numbers on an Idaho License Plate Mean?

The beginning characters on a standard Idaho license plate identify the county where the vehicle is registered.

For example, a plate beginning with 1A indicates Ada County (which contains Boise, the state capital).

The system is arranged alphabetically by county name using a consistent two-part logic:

• The letter represents the first letter of the county name.
• The leading number indicates that county’s alphabetical rank among all Idaho counties sharing that same initial letter.

Because Idaho has ten counties that begin with the letter “B,” their codes run from 1B through 10B based on their alphabetical order:

• 1A — Ada County
• 2A — Adams County
• 1B — Bannock County
• 2B — Bear Lake County
• 3B — Benewah County
• 4B — Bingham County
• 5B — Blaine County
• 6B — Boise County
• 7B — Bonner County
• 8B — Bonneville County
• 9B — Boundary County
• 10B — Butte County

This system turns every Idaho license plate into an open puzzle for road-trip spotters who know how to read the prefixes.

What Does 1A Mean on an Idaho License Plate?

1A means Ada County.

Boise is located inside Ada County, making 1A the single most common county designator spotters will encounter on highways across Idaho and neighboring Western states.

The code reflects the state’s alphabetical naming structure: Ada and Adams are Idaho’s only two counties starting with the letter “A.” Since Ada comes before Adams in the alphabet:

• 1A = Ada County (Boise)
• 2A = Adams County (Council)

Notable Idaho County Codes

While Ada County (1A) is the most frequent sighting, spotters can quickly identify major population hubs and scenic regions by their county prefixes:

Idaho has 44 counties, each represented within the county-designator system.

See Idaho Transportation Department for the complete 44-county directory →

Idaho Centennial — 1890–1990

In the late 1980s leading up to its 1990 statehood centennial, Idaho offered an optional celebratory plate design featuring red, white, and blue horizontal bands.

According to the Idaho State Historical Society, the Centennial plate prominently displayed “1890 Idaho 1990” along with the word “Centennial.”

The design proved wildly popular with Idaho residents, establishing the striking red, white, and blue visual balance that would directly inspire the state’s modern Scenic Idaho base plate.

The Red, White and Blue “Scenic Idaho” Plate

Following the centennial celebration, Idaho introduced its iconic modern standard plate in 1991.

The Idaho Transportation Department officially designates this format as the red, white and blue Scenic Idaho plate. Its instantly recognizable design features:

• A bold red band across the top border
• A crisp white center with dark embossed or printed numerals
• A deep blue band across the bottom edge
• A stylized mountain and forest landscape silhouetted in the background
• “IDAHO” rendered prominently at top
• The timeless “Famous Potatoes” tagline across the lower field
• The county designator positioned at the far left

Why Is Idaho’s License Plate Red, White and Blue?

Idaho’s plate colors originated directly from the 1990 Centennial design rather than any formal legislative decree assigning symbolism to each shade.

When the state designed the 1890–1990 Centennial plate, designers chose red, white, and blue to celebrate a century of American statehood. When Idaho motorists embraced the look over previous plain backgrounds, state officials carried the tri-color mountain motif forward into the permanent standard plate in 1991.

Idaho Goes Digital — 2007

According to the Idaho Transportation Department, Idaho began transitioning from traditional stamped metal plates with embossed characters to digitally produced flat plates in 2007.

Digital printing allowed the state to produce crisp photographic mountain backdrops and sharp typography directly onto durable flat aluminum sheeting, streamlining county fulfillment. Existing embossed plates were not recalled; Idaho continued issuing existing warehouse stocks until depletion, allowing older stamped plates to remain in everyday highway use alongside flat plates for years.

Idaho License Plates Changed in 2026

On July 1, 2026, Idaho implemented two major structural changes to its vehicle registration system under House Bills 533 and 577.

Registration stickers ended

Idaho formally stopped issuing and requiring annual physical registration stickers on vehicle license plates.

Drivers must continue to renew their vehicle registration on time, but the physical plates no longer carry month or year decals. Law enforcement officers now verify vehicle registration electronically through direct database queries.

Plates became permanent

Idaho also eliminated the mandatory replacement cycle that previously required drivers to purchase new license plates every 10 years.

Plates can now remain in service indefinitely as long as they stay readable, legible, and structurally intact. Motorists only need to order replacement plates if a plate becomes damaged, faded, or unreadable.

SOURCE: Idaho Transportation Department, June 30, 2026.

Idaho’s New Black-and-White Standard Plate

Beginning July 1, 2026, the Idaho Transportation Department introduced a brand-new standard plate option: a minimalist, high-contrast white-and-black Idaho plate.

The design features stark black letters and numbers printed against a clean, solid white field. ITD introduced the look as a modern, clutter-free option designed for maximum visual contrast and legibility.

Crucially, this is a standard plate option, not a specialty plate tied to a specific non-profit or interest group. Idaho drivers can choose between the classic red, white and blue Scenic Idaho plate and the new black-and-white design when registering their vehicle.

SOURCE: Idaho Transportation Department, June 26, 2026.

Two Standard Designs You May See

As a result of the 2026 changes, road-trip spotters will now observe two fundamentally different standard Idaho license plate designs on the highway:

Idaho Specialty License Plates

In addition to its standard passenger plates, the Idaho Transportation Department offers more than 40 specialty license plate designs.

These plates allow motorists to support specific state programs, colleges, youth organizations, and conservation funds. Notable categories and popular designs include:

• Wildlife & Conservation: Appaloosa horse, elk, cutthroat trout, and bluebird designs
• Recreation & Landscapes: Sawtooth Mountains, Whitewater Rafting, and Ski Idaho
• Colleges & Universities: Boise State University, University of Idaho, and Idaho State University
• Agriculture: The Idaho Agriculture “Harvest the Future” plate supporting Ag in the Classroom
• Military & Veterans: Commemorative branches, Medal of Honor, and Purple Heart

Explore all specialty designs in the ITD License Plate Catalog →

World Famous Potatoes Specialty Plates

Idaho’s potato heritage also extends beyond the standard “Famous Potatoes” tagline. Idaho has issued dedicated specialty plates featuring the expanded “World Famous Potatoes” slogan, offering collectors and enthusiasts a distinctive agricultural tag with stylized potato graphics and custom color treatments.

Idaho Plate Spotter’s Guide

Idaho License Plate FAQ

Why does Idaho say Famous Potatoes on its license plate?

Idaho adopted “Famous Potatoes” to celebrate and promote its primary agricultural crop. Ideal growing conditions in the Snake River valley established Idaho as the leading potato-producing state in America, and the slogan became an enduring badge of state pride on vehicle bumpers.

When did potatoes first appear on an Idaho license plate?

1928. According to the Idaho State Historical Society, the 1928 plate featured “Idaho Potatoes” printed over an embossed illustration of a potato, making Idaho the first state in the nation to place an official promotional slogan on a license plate.

When did “Famous Potatoes” first appear?

1957. The shortened, iconic phrase “Famous Potatoes” debuted in 1957 and has continued on standard Idaho passenger tags for nearly seven decades.

What does 1A mean on an Idaho license plate?

Ada County. Ada County encompasses Boise, the state capital, making 1A the most common county designator in Idaho.

What do Idaho license plate letters mean?

On standard Idaho plates, the initial letter and number indicate the county of registration. The letter matches the first letter of the county name, while the number indicates that county’s alphabetical order among all Idaho counties starting with that letter.

What county is 1K in Idaho?

Kootenai County. Kootenai County (home to Coeur d’Alene) is Idaho’s sole county beginning with the letter “K,” designated as 1K.

What does 2C mean on an Idaho license plate?

Canyon County. In the “C” county group, Camas County is 1C and Canyon County (Caldwell and Nampa) is 2C.

What does the current Idaho license plate look like?

Idaho currently offers two standard passenger options: the classic red, white, and blue Scenic Idaho plate featuring mountains and the “Famous Potatoes” slogan, and a minimalist white-and-black plate option introduced on July 1, 2026.

Does Idaho still use registration stickers?

No. As of July 1, 2026, Idaho eliminated annual physical registration stickers. Drivers must keep their vehicle registration current, but stickers are no longer placed on license plates.

How often does Idaho replace license plates?

Under legislation effective July 1, 2026, Idaho moved to permanent license plates and removed the mandatory 10-year replacement cycle. Plates can now remain in service indefinitely as long as they stay legible and undamaged.

Does Idaho require a front license plate?

Only if equipped with a factory bracket. Under Idaho Code § 49-428 (effective July 1, 2025), a front license plate is only required if the vehicle is manufactured or equipped with a front mounting bracket. If a vehicle has no front bracket, owners are not required to drill holes or install aftermarket mounts and may legally display a rear plate only.

Where Are You Likely to Spot an Idaho Plate?

Idaho plates are frequent sights across the Pacific Northwest and the Mountain West. Neighboring states — Washington, Oregon, Montana, Utah, Wyoming, and Nevada — see high volumes of Idaho traffic year-round.

Because Idaho sits at the crossroads of major outdoor recreation corridors, spotters frequently encounter Idaho plates near Yellowstone and Grand Teton National Parks, along the Columbia River Gorge, and traveling the Interstate 84, Interstate 15, and Interstate 90 highway arteries.