Michigan businesses operating under a name different from the owner's last name must register that name with the state. In Michigan, like in other states, these sometimes are referred to as trade names, "doing business as" names, assumed names or aliases. Depending on the type of business you have, you will be required to register your business name at either the county or state level.

Unique Name

Michigan requires business trade names to be unique from other business names used in the state. Check local and state databases to make sure your chosen name isn't already taken. To check your business name at the state level, conduct a name availability search on the Department of Licensing and Regulatory Affairs website. The search results will list businesses registered at the state level. Next, conduct a search at the county level, focusing on where your business is located. This is done through the county clerk's office. Many county offices, including Ottawa County, Oakland County and Macomb County, also provide online access to their name databases.

Assumed Name vs. Co-Partnership Name

If your business is a sole proprietorship or general partnership, called a co-partnership in Michigan, register your business name with the county clerk's office. There are two types of name registrations at the county level: assumed name and co-partnership name. Businesses with one or more owners can file an assumed name registration. With this type of registration, changes to the business cannot be made at a later date without the written authorization of each owner who signed the original document. Co-partnership name registrations are limited to businesses with two or more owners. Only one owner is required to sign the name registration form, in front of a notary public. With this registration type, future changes can be made by any owner of the business.

Registration With County Clerk

Obtain the assumed name or co-partnership name registration application from the county clerk's office. You usually can pick up the form in-person or have it mailed to you. Some county clerks, such as those of Oakland County and Ottawa County, make the forms available online. Information required on these forms includes owners' names and addresses, as well as the chosen business name and location. Some forms also require a description of the business' purpose. Sign the form in front of a notary public and deliver to the county clerk's office in person or by mail along with filing fee, which also differs between counties.

State Registration 

Michigan requires corporations, limited liability companies and limited partnerships to register with the state Department of Licensing and Regulatory Affairs. Complete a Certificate of Assumed Name form, which is available on the department's website along with other corporate forms and publications. The completed form may be mailed to the Michigan Department of Licensing and Regulatory Affairs, Corporations, Securities & Commercial Licensing Bureau, Corporations Division, P.O. Box 30054, Lansing, MI 48909. If the business is a corporation or limited partnership, include a $10 filing fee. If it is a limited liability company, the filing fee is $25. You also can deliver the completed form in person to 2501 Woodlake Circle, Okemos, MI 48864.