To check a business name in Idaho, use the Idaho Secretary of State’s free SOSBiz business search. Search the distinctive words of your name and confirm that no existing entity or assumed business name on record is the same or too close.
Idaho rewards filing online. A name reservation costs $20 in SOSBiz (versus $40 on paper) and holds the name for four months. An assumed business name, Idaho’s term for a DBA, costs $25 online and stays active until you cancel it, with no renewals.
Updated October 2026.
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Best LLC Formation Services in Idaho (2026)
If you’d rather not handle forming your LLC once your name is clear in Idaho yourself, these are the services we recommend, in order. The table compares price and what’s included.
| Rank | Provider | Best for | Price | What’s included |
|---|---|---|---|---|
| 1 | Mainstay Filing | Forming an LLC with the agent, EIN and annual report included | $199/year + state fee at cost | LLC formation filing, registered agent for the year, EIN application, annual report preparation and filing |
| 2 | ID Registered Agent.org | Idaho registered agent service only | $99/year | $99 per year, flat; in-state street address for the registered office; legal documents served on the company are scanned and sent to the owner online |
| 3 | Idaho Registered Agent.co | Idaho registered agent service only | $99/year | in-state street address for the registered office; legal documents served on the company are scanned and sent to the owner online |
1. Mainstay Filing
Mainstay Filing is our top pick in Idaho. It costs $199/year + state fee at cost and covers lLC formation filing, registered agent for the year, EIN application, annual report preparation and filing. The price stays the same every year, with no add-on menu.
2. ID Registered Agent.org
ID Registered Agent.org is a Idaho registered agent service at $99/year. It provides $99 per year, flat; in-state street address for the registered office; legal documents served on the company are scanned and sent to the owner online. It’s a fit if you only need a registered agent rather than full formation help.
3. Idaho Registered Agent.co
Idaho Registered Agent.co is a Idaho registered agent service at $99/year. It provides in-state street address for the registered office; legal documents served on the company are scanned and sent to the owner online. It’s a fit if you only need a registered agent rather than full formation help.
Idaho name search: the essentials
| Topic | Idaho (as of October 2026) |
|---|---|
| Filing office | Idaho Secretary of State, Business Services |
| Search tool | SOSBiz business search (free) |
| Name reservation | $20 online; $40 paper; lasts 4 months |
| Certificate of Organization (LLC) | $100 online; $120 paper |
| Assumed business name (DBA) | $25 online; $45 paper; no renewal required |
| Paper surcharge | Every paper filing carries a $20 manual processing fee |
| Annual report | Required each year; no filing fee when filed online in SOSBiz |
| Online filing | SOSBiz |
Fees are from the Secretary of State’s business forms page. Mainstay Filing’s Idaho LLC cost guide totals the startup costs.
How to use the Idaho Secretary of State business search
SOSBiz is the Secretary of State’s filing and records system for Idaho businesses. Searching is free, and you don’t need an account.
Search the core of the name
Open the business search and type the key words of your proposed name, leaving off “LLC” or “Inc.” Searching “Sawtooth Supply” will surface “Sawtooth Supply Co.” and “Sawtooth Supply LLC” if they exist.
Include assumed business names in your review
Assumed business names are filed with the Secretary of State in Idaho, so they appear alongside entities in SOSBiz. Read every close result, not just LLCs and corporations.
Check the record’s status
Open each similar record to see its type and status. An active entity or reservation with a name that isn’t distinguishable from yours will block your filing unless the holder consents.
Look at trademarks too
SOSBiz has a separate trademark search for Idaho state trademarks. A registered state mark doesn’t stop the filing, but it is a warning sign.
Remember that a search is information only. It doesn’t hold the name; a reservation or a formation filing does.
Idaho name rules
- Distinguishable on the record: a new entity or assumed business name must be distinguishable from names already registered with the Secretary of State.
- Consent letters: according to the Secretary of State’s business FAQ, if your assumed business name isn’t distinguishable from a registered name, you need written consent from the holder. If you’re unsure, contact Business Services before filing.
- LLC designator: an Idaho LLC name must include “limited liability company” or an accepted abbreviation such as “LLC” or “L.L.C.”
- Corporate designator: a corporation needs “corporation,” “incorporated,” “company” or “limited,” or an abbreviation.
- Regulated words: names that suggest banking, insurance or a licensed profession may need approval from the relevant Idaho regulator.
Looking for alternatives? Namechk’s business name generator creates options to test in SOSBiz.
How to reserve a business name in Idaho
A reservation gives you time to prepare your filing without losing the name. Here’s how it works:
- File online in SOSBiz for $20, or mail the Application for Reservation of Legal Entity Name with $40 ($20 base fee plus the $20 manual processing fee).
- Wait for approval. Once approved, the reservation lasts four months.
- File your Certificate of Organization or Articles of Incorporation under the reserved name before the four months run out.
Paper submissions that leave out the $20 manual processing fee are rejected, which is one more reason to file online.
Common mistakes in an Idaho name search
Most rejected or regretted Idaho names trace back to a handful of avoidable errors:
- Searching the full name with its ending. Typing “Sawtooth Supply LLC” can hide a “Sawtooth Supply Inc.” that blocks you. Search the core words.
- Ignoring assumed business names. An ABN on record can require a consent letter for a similar ABN, so read those results too.
- Treating a reservation as a DBA. A reservation holds an entity name for four months; it doesn’t let you trade under that name. An ABN does that.
- Mailing paper forms without the manual fee. The Secretary of State rejects paper filings that leave out the $20 processing fee.
- Assuming an ABN gives you exclusive rights. It’s a public record of who is behind a name, not a business license or a trademark.
Trademark, domain and social media checks
Idaho’s records don’t include federal trademarks. Search the USPTO trademark database for identical or similar marks, especially in your own industry.
Then make sure you can claim the name online. Namechk checks domain names and social media handles in one search. If the .com is taken, the domain name generator can suggest close alternatives.
We created a tool that makes it easy.
Filing an assumed business name (DBA) in Idaho
Idaho calls a DBA an assumed business name (ABN). It lets a business operate under a name other than its legal name, and it is filed with the Secretary of State, not a county.
- Fee: $25 online in SOSBiz, or $45 on the paper Certificate of Assumed Business Name.
- Duration: an ABN stays active until the owner cancels it. It isn’t subject to renewal.
- Changes: amending an ABN requires a filing fee; cancelling online is free.
- Limits: an ABN doesn’t create a separate legal entity and isn’t a business license.
- Consent: if the ABN isn’t distinguishable from a registered name, you need the holder’s written consent.
Note from the Secretary of State’s business services page: an assumed business name can’t serve as a registered agent.
After the search: forming an Idaho business
Once you’ve confirmed the name, our Idaho LLC guide covers the rest. The short version:
- File a Certificate of Organization in SOSBiz ($100 online).
- Appoint a registered agent with an Idaho physical address. You can serve yourself or use a service; Mainstay Filing includes one with formation. See our Idaho registered agent guide.
- Get an EIN from the IRS and register with the Idaho State Tax Commission if needed.
- File the annual report online each year by the end of your anniversary month; there’s no fee, but an LLC that skips it can be dissolved. Our Idaho start-a-business guide lists other licenses to check.
FAQs
How do I search for a business name in Idaho?
Use SOSBiz, the Idaho Secretary of State’s online business system. Its business search is free and shows registered entities and assumed business names. Search the distinctive words of your name without LLC or Inc., open close matches to check their status, and also run the SOSBiz trademark search for Idaho state trademarks.
How much does it cost to reserve a business name in Idaho?
Reserving a legal entity name in Idaho costs $20 online through SOSBiz or $40 on paper, which includes a $20 manual processing fee. Once approved, the reservation lasts four months. Paper filings submitted without the manual processing fee are rejected, so online filing is cheaper and simpler.
How do I file a DBA in Idaho?
File a Certificate of Assumed Business Name with the Idaho Secretary of State. It costs $25 online in SOSBiz or $45 on paper. An assumed business name stays active until you cancel it and doesn’t need renewal. If it isn’t distinguishable from a registered name, you need written consent from that name’s holder.
Do Idaho assumed business names expire?
No. According to the Idaho Secretary of State, an assumed business name stays active until the owner cancels it and isn’t subject to renewal. Amendments carry a filing fee, while cancelling online is free. An assumed business name doesn’t create a separate legal entity and isn’t a business license.
What does an Idaho LLC cost to form?
The Idaho Secretary of State charges $100 to file a Certificate of Organization online, or $120 on paper because of the $20 manual processing fee. You’ll also need a registered agent with an Idaho address and must file an annual report online each year to stay in good standing.
Does an Idaho business search guarantee a name is available?
No. A SOSBiz search shows what’s on record today, but it doesn’t hold the name, and the Secretary of State decides availability when it reviews your filing. Reserve the name for $20 online if you need time, and check federal trademarks before investing in branding.
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