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Tax Extension + Payment Planner

Recommended payment to submit with your extension to avoid underpayment interest. Uses IRS safe-harbor rules (100% or 110% of prior-year tax, or 90% of current-year estimate).

Filing Status

Prior-year total tax ($)

Prior-year AGI ($)

YTD federal withholding ($)

YTD estimated-tax payments ($)

Expected CURRENT-year AGI ($)

Expected CURRENT-year total tax ($)

Limitations: US federal only. State safe-harbor rules differ (California uses 90%/100% with its own AGI threshold). Does NOT compute your actual tax liability — you supply the estimate. Does NOT model quarterly-estimated-payment penalties on the quarters you underpaid.

What to do next: Extension = extra TIME to FILE, not extra time to PAY. Submit at least the safe-harbor floor with Form 4868 by the April deadline. Keep the IRS payment confirmation.

Not tax advice. Consult a CPA for complex situations (1099 income, K-1s, AMT, withholding changes).