Gillock CPA Resource Center
Tax & Business Resources
Important dates, trusted links, and practical guidance for business owners.
Practical Guides
A clearer starting point.
Useful questions, checklists, and explanations for your next financial decision.
Tax Preparation
Tax Preparation Document Checklist
Gather common personal and business records, track missing items, and share sensitive information safely.
Read the checklist
Financial Reporting
Review vs. Audit
Understand assurance levels and the questions to ask before choosing a financial statement engagement.
Compare review and audit
Business Planning
When to Consider a Fractional CFO
Identify forward-looking questions, useful deliverables, and the right scope for your business.
Explore CFO readinessPlan ahead
Common Annual Tax Deadlines
Typical federal dates for calendar-year taxpayers. A planning guide, not a complete filing calendar.
Estimated Tax Payment
Final individual estimated payment for the prior tax year.
Business Return Deadline
Calendar-year partnership and S corporation returns generally due.
Individual Return Deadline
Individual and calendar-year C corporation returns generally due.
Weekend and legal-holiday rules, disaster relief, fiscal years, and other exceptions can change these dates. State deadlines may differ. A filing extension generally does not extend payment deadlines.
More common federal deadlines
| Deadline | Common filing or payment |
|---|---|
| January 15 | Final individual estimated tax payment for the prior tax year. |
| January 31 | Deliver W-2s to employees and file with the SSA. Deliver 1099-NEC statements to recipients and file with the IRS. |
| January 31 | Generally deliver 1099-MISC statements to recipients; certain statements have a February 15 deadline. |
| February 28 | File paper 1099-MISC returns with the IRS, if eligible to file on paper. |
| March 15 | Calendar-year partnership and S corporation returns, or timely extension requests. |
| March 31 | File electronic 1099-MISC returns with the IRS. |
| April 15 | Individual and calendar-year C corporation returns and payments; first individual estimated tax payment. |
| June 15 | Second individual estimated tax payment. |
| September 15 | Third individual estimated payment; extended calendar-year partnership and S corporation returns. |
| October 15 | Extended individual and calendar-year C corporation returns, generally. |
Check current guidance: IRS tax calendar, 1099 filing and delivery, and W-2 deadlines. Sources checked September 21, 2026.
Trusted sources
Helpful Tax Links
Federal Tax Links
Forms, payments, refunds, and other official IRS resources.
Oregon, California & Washington
Official state filing, payment, and business tax information.
Record Retention Guide
Keep records by purpose—not a single blanket deadline.
- Filed tax returnsRetain copies for future reference.
- Supporting tax recordsThe retention period depends on the return and circumstances; seven years is not a universal rule.
- Employment tax recordsAt least four years after the tax is due or paid, whichever is later.
- Property and basis recordsKeep through ownership and the applicable tax-record period after disposal.
State rules, legal matters, lenders, and insurers may require longer retention. Confirm before destroying records.
Read IRS record-retention guidance →A useful starting point
Guidance tailored to your business
Online resources are helpful, but the right tax strategy depends on your entity, industry, goals, and filing history. Gillock CPA provides year-round planning and preparation for businesses in Oregon, California, and Washington.
Please note: This page provides general information and is not tax, legal, or accounting advice. Deadlines and requirements may change. Consult a qualified professional about your specific circumstances.