DBA · Idaho

How to File an Assumed Name for an LLC in Idaho

By Edmond Hui · Last updated October 6, 2026

Short answer

Idaho requires an LLC that does business under a name other than its own to register an assumed name. A foreign LLC that registered in Idaho under an alternate name, because its own name was not available, does not file a certificate for that alternate name. An LLC files the Certificate of Assumed Business Name with the Secretary of State.

Idaho Assumed Name at a Glance

Requirement: Required
Where to file: Secretary of State
Fee: See Cost and renewal
How long it lasts: No fixed term
Newspaper notice: None found
File online: Yes

How an LLC Files

File before starting to do business under the name.

An LLC files the Certificate of Assumed Business Name with the Secretary of State.

You can file online.

Open the filing office's site · Open the filing page

Cost and Renewal

Filing online through SOSBiz costs $25. A paper certificate costs $45, the $25 filing fee plus a $20 manual processing fee.

The registration has no fixed term.

The certificate stays in effect from filing until you cancel it.

Publication

We found no publication step for an LLC's assumed name filing in Idaho.

Does it protect the name?

Registering does not give the LLC ownership of, or an exclusive right to, the name.

If you skip it

A business trading under an unfiled assumed business name cannot bring a lawsuit in an Idaho court until it files the certificate. Anyone who suffers a loss because of the failure to file can recover damages plus attorney's fees and costs.

Sole proprietors

Idaho requires a sole proprietor who does business under a name other than their legal name to register an assumed name. An individual or general partnership needs a certificate when the business name does not include the full true names of everyone with a financial interest in the business. An individual using both their legal first and last name in the business name does not need one.

File before starting to do business under the name.

A sole proprietor files the Certificate of Assumed Business Name with the Secretary of State.

Filing online through SOSBiz costs $25. A paper certificate costs $45, the $25 filing fee plus a $20 manual processing fee.

The registration has no fixed term.

The certificate stays in effect from filing until you cancel it.

We found no publication step for a sole proprietor's assumed name filing in Idaho.

Requirement	Required
Where to file	Secretary of State
Fee	See Cost and renewal
How long it lasts	No fixed term
Newspaper notice	None found
File online	Yes

Next steps

Frequently Asked Questions

: Idaho requires an LLC that does business under a name other than its own to register an assumed name. A foreign LLC that registered in Idaho under an alternate name, because its own name was not available, does not file a certificate for that alternate name. File before starting to do business under the name.
: An LLC files the Certificate of Assumed Business Name with the Secretary of State.
: Filing online through SOSBiz costs $25. A paper certificate costs $45, the $25 filing fee plus a $20 manual processing fee.
: The registration has no fixed term. The certificate stays in effect from filing until you cancel it.
: We found no publication step for an LLC's assumed name filing in Idaho.
: Registering does not give the LLC ownership of, or an exclusive right to, the name.
: A business trading under an unfiled assumed business name cannot bring a lawsuit in an Idaho court until it files the certificate. Anyone who suffers a loss because of the failure to file can recover damages plus attorney's fees and costs.
: Idaho requires a sole proprietor who does business under a name other than their legal name to register an assumed name. An individual or general partnership needs a certificate when the business name does not include the full true names of everyone with a financial interest in the business. An individual using both their legal first and last name in the business name does not need one. A sole proprietor files the Certificate of Assumed Business Name with the Secretary of State.

This guide is general information, not legal or tax advice, and reading it does not create an attorney-client relationship. It reports what each state's filing office publishes about registering a business name, with the sources this page cites. A filing here does not register a federal trademark, and fees and forms change between our reviews. Confirm with the office named on this page before you file.

Sources

Each entry below is a document recorded in our verified Idaho sources, and each entry says what the document is. Some statutory text is read from an accurate mirror rather than from the state's own host, and those say so.

legislature.idaho.gov/wp-content/uploads/statutesrules/idstat/Title30/T30CH21.pdfIdaho Code Title 30 Chapter 21, Part 8 (Idaho Assumed Business Names Act) and 30-21-214 (Fees)
sos.idaho.gov/business-resources/business-faq/Idaho Secretary of State, Frequently Asked Questions For Business
sos.idaho.gov/business-forms/Idaho Secretary of State, Business Forms
archive.sos.idaho.gov/CORP/forms/ABN/ABN.pdfIdaho Secretary of State, Certificate of Assumed Business Name form (rev. 01/2019)
sosbiz.idaho.gov/search/businessIdaho Secretary of State, SOSBiz Business Search
legislature.idaho.gov/wp-content/uploads/statutesrules/idstat/Title30/T30CH21.pdfIdaho Code 30-21-506, Noncomplying name of foreign entity

Edmond Hui · Founder, MyStateLLC

Edmond Hui is a software engineer and serial entrepreneur based in New York who has founded multiple online businesses across e-commerce, media, and information publishing. Before transitioning into tech, he spent years as a commercial real estate professional closing deals totaling over 100,000 square feet, giving him firsthand experience with business formation and entity structuring. He built MyStateLLC to provide the free, state-specific LLC guidance he wished existed when forming his own companies.