The following links may be useful for business startups, existing businesses, business owners, business buyers and business sellers. If you are buying a business or selling a business you and or your business broker or intermediary will find them helpful.
Arizona Department of Revenue
Many Business Tax Forms and Other Business Ownership Information
https://www.azdor.gov/business.aspx
Arizona Department of Economic Security
Information Regarding Unemployment Tax for Employers
https://roc.az.gov/

Arizona Department of Transportation
Motor Vehicle Information for Employers
https://www.azdot.gov/mvd

Arizona Registrar of Contractors
Requirements & Search for Licensing & Contractors
https://roc.az.gov/

Arizona Corporation Commission
Information & Forms to Create Legal Entities & Search for Existing Entities
http://ecorp.azcc.gov/

Arizona Secretary of State
Trade Name & Trademarks Registration & UCC Guidelines
http://www.azsos.gov/business

Maricopa County Recorder
Search for Recorded Documents
http://recorder.maricopa.gov/recdocdata/

Maricopa County Assessor
Search for Real Property Ownership
http://mcassessor.maricopa.gov/

SCORE
Business Mentoring & Advice
https://greaterphoenix.score.org/chapters/greater-phoenix-score

Small Business Administration
Loans, Grants, Assistance for Business
https://www.sba.gov/

Internal Revenue Service
Online EIN Application
https://www.irs.gov/Businesses/Small-Businesses-&-Self-Employed/Apply-for-an-Employer-Identification-Number-(EIN)-Online
Forms, Publications for Business
https://www.irs.gov/Forms-&-Pubs