18.4 Estimated Tax Payments
Key Takeaways
- Required if expecting to owe $1,000+ after withholding/credits.
- Due dates: April 15, June 15, September 15, January 15.
- Safe harbor: 90% current year OR 100% prior year tax.
- High-income (AGI >$150k): Must pay 110% of prior year.
- Underpayment penalty calculated on Form 2210.
- Annualized income method available for seasonal businesses.
Why This Matters for the Exam
Estimated tax is tested every exam. Know the due dates, safe harbor rules, and high-income exception.
Expect at least 2-3 questions on estimated taxes.
Who Must Pay?
You must make estimated tax payments if:
| Requirement | Threshold |
|---|---|
| Expected tax owed | $1,000 or more |
| Withholding/credits | Less than 90% current year OR 100% prior year |
Quarterly Due Dates
| Period | Income Period | Due Date |
|---|---|---|
| 1st | Jan 1 - Mar 31 | April 15 |
| 2nd | Apr 1 - May 31 | June 15 |
| 3rd | Jun 1 - Aug 31 | September 15 |
| 4th | Sep 1 - Dec 31 | January 15 (next year) |
Safe Harbor Rules
To avoid penalty, pay at least:
| Test | Requirement |
|---|---|
| Current year | 90% of current year tax |
| Prior year | 100% of prior year tax |
| Meet either | Safe harbor satisfied |
High-Income Exception
| Prior Year AGI | Safe Harbor |
|---|---|
| ≤$150,000 | 100% of prior year |
| >$150,000 | 110% of prior year |
| MFS >$75,000 | 110% of prior year |
Safe Harbor Example
| Item | Amount |
|---|---|
| 2023 tax liability | $10,000 |
| 2023 AGI | $180,000 |
| 2024 estimated tax requirement | $10,000 × 110% = $11,000 |
Underpayment Penalty
| Feature | Rule |
|---|---|
| Calculation | Form 2210 |
| Rate | IRS interest rate (quarterly) |
| Per quarter | Penalty calculated separately |
| No forgiveness | Late Q1 not fixed by early Q4 |
Annualized Income Method
For seasonal businesses or businesses that start mid-year:
| Feature | Benefit |
|---|---|
| Form | Form 2210, Schedule AI |
| Effect | Base payments on actual income each period |
| Example | Business starts in October—no Q1-Q3 payments required |
Special Rules: Farmers and Fishermen
| Rule | Description |
|---|---|
| Single payment | One payment by January 15 |
| Alternative | File return and pay by March 1 |
| Threshold | ≥2/3 of gross income from farming/fishing |
Real-World Scenario
Scenario: Taxpayer expects to owe $8,000 for Tax Year 2024. Prior year tax was $6,000. Prior year AGI was $140,000.
- Current year 90%: $8,000 × 90% = $7,200.
- Prior year 100%: $6,000.
- Safe harbor: Pay at least $6,000 (lesser of two tests).
- Quarterly payments: $6,000 ÷ 4 = $1,500 each quarter.
High-Income Scenario
Scenario: Prior year tax $50,000. Prior year AGI $200,000.
- Safe harbor: 110% of prior year = $55,000.
- Quarterly payments: $55,000 ÷ 4 = $13,750 each quarter.
On the Exam
Expect 2-3 questions on estimated taxes, typically:
- Due Date Questions: "When is Q3 estimated tax due?"
- Safe Harbor Questions: "What is the safe harbor for AGI >$150k?"
- Threshold Questions: "What triggers estimated tax requirement?"
The key is to remember: $1,000 threshold. Due Apr 15, Jun 15, Sep 15, Jan 15. Safe harbor = 90% current OR 100% prior. High-income = 110% prior.
Taxpayer expects $5,000 tax. Prior year was $4,000, AGI $100,000. Minimum safe harbor payment?
Prior year: AGI $200,000, tax $40,000. Minimum estimated tax for current year under prior-year safe harbor?
When is the 3rd quarterly estimated tax payment due?