Many Phoenix and Arizona small businesses operate as S-Corporations. While S-Corps offer liability protection and tax advantages, the filing requirements can be complex — especially with basis limitations, K-1 reporting, and Arizona conformity rules.
Key S-Corp Filing Deadlines for 2026
- Federal Form 1120-S: March 15, 2026 (or September 15 with extension)
- Arizona S-Corp return: Same as federal (Arizona conforms closely)
- Estimated tax payments: Quarterly (next one September 15, 2026)
Important 2026 Considerations for S-Corps
- QBI Deduction: Still available and permanent. Reasonable compensation to shareholder-employees is critical to maximize it.
- Basis Limitations: Suspended losses from prior years may become deductible if basis is restored.
- K-1 Reporting: Accurate K-1s are essential for shareholders’ individual returns.
- Arizona Conformity: Arizona follows many federal rules but has its own small business income tax considerations.
Common Mistakes to Avoid
- Not paying yourself reasonable compensation as a shareholder-employee.
- Ignoring basis tracking throughout the year.
- Missing Arizona-specific credits or estimated payment requirements.
- Waiting until the last minute to gather records for K-1s.
Action Steps for S-Corp Owners
- Review your 2025 K-1s and basis calculations.
- Project 2026 income and estimated payments.
- Document all shareholder loans and contributions.
- Schedule a mid-year review with your tax advisor.
Need Help With Your S-Corp Taxes?
Vault Financials specializes in S-Corp compliance and tax planning for Arizona businesses. We can help you minimize taxes, stay compliant, and avoid costly mistakes.
Contact us today for a consultation.
Disclaimer: This article is for educational purposes only. Tax laws are complex and individual situations vary. Consult a qualified tax professional.