Freelancer Tax Compliance Checklist

As a freelancer, I want to make sure I'm fully tax compliant. Create a comprehensive compliance guide for me.

My freelance details:
- Type of freelance work: [Industry/Services]
- Annual freelance income: [Amount]
- Number of clients: [Number]
- Work with businesses (will receive 1099s): [Yes/No]
- Also have W-2 employment: [Yes/No]
- Business structure: [Sole Prop/LLC/Other]
- State(s) where clients are located: [States]
- Years freelancing: [Number]

Please provide:
1. Complete tax obligation checklist
2. All forms I need to file
3. Important deadlines throughout the year
4. Estimated tax payment requirements
5. Self-employment tax calculation
6. Required record-keeping practices
7. 1099 issuance requirements if I use subcontractors
8. State tax nexus considerations
9. Retirement account options
10. Business license and registration requirements