What Is the Abbreviation for Idaho?
The standard abbreviation for Idaho is ID. This page explains why Idaho uses ID, how the code fits into the modern USPS system, what older printed abbreviations looked like, and which nearby or similar state codes people commonly confuse with it.
What Is the Abbreviation for Idaho?
Idaho is abbreviated ID. ID is the form used in mailing addresses, forms, databases, and current style guides.
Use ID for Idaho in mailing addresses, shipping labels, and official records.
Why Idaho Uses ID
Idaho's USPS abbreviation is ID.
ID has been Idaho's standard postal abbreviation since 1963 and is the form used in current addresses, forms, and databases.
Old Abbreviation for Idaho
Before the USPS two-letter system became the mailing standard in 1963, printed reference books and newspapers often used longer abbreviations with punctuation. For Idaho, that older style was usually Idaho.
That older form still appears in historical texts, archival material, and some legacy style guides, but the modern postal and database standard is ID. If someone searches for old abbreviation for Idaho, the practical answer is to recognize Idaho and use ID in current writing and addresses.
How to Write Idaho in an Address
In standard American addressing, the state line uses the city name followed by the two-letter code and ZIP Code. The abbreviation stays uppercase and does not take periods.
That same format applies in checkout forms, school worksheets, CRM exports, spreadsheets, shipping labels, and government databases — anywhere a two-letter state code is required.
ID Compared With Similar State Codes
ID can be unclear outside an address because the same letters are widely used as shorthand for identification.
Related Abbreviation Questions
These states share a first letter, region, or alphabetical position with Idaho and are commonly checked alongside it.
Capital, Region, and Context
Idaho belongs to the West region. Its capital is Boise, and its postal code ID is used in addresses, forms, and databases throughout the country.
Idaho entered the Union on July 3, 1890.
FAQ
What is the abbreviation for Idaho?
The standard USPS abbreviation for Idaho is ID.
What is the postal abbreviation for Idaho?
ID is the two-letter postal abbreviation for Idaho. It is the form used in mailing addresses, shipping labels, forms, and databases.
How do you abbreviate Idaho?
Abbreviate Idaho as ID in current USPS, mailing, and database use.
Why is Idaho abbreviated ID?
Idaho's USPS abbreviation is ID.
What does ID stand for?
ID stands for Idaho in the USPS state abbreviation system.
What is the old abbreviation for Idaho?
Older editorial styles often wrote Idaho as Idaho. For mailing and database use, the modern standard is ID.
How do you write a Idaho mailing address?
Use the city name, then the two-letter postal code ID, then the ZIP Code. For example: Boise, ID 00000.
What state is ID?
ID is the postal abbreviation for Idaho, located in the West region. The capital is Boise.
Test All 50 State Abbreviations
Now that you know ID stands for Idaho, see how many of the other 49 you can get right. The M-states and I-states trip up most people.