---
title: "Quarterly estimated-tax package (Form 1040-ES): derives your current-year total tax (federal income + self-employment + FICA + state) from income, applies the safe harbor (lesser of 90% current or 100%/110% prior-year tax), and returns the four equal 2026 installments net of withholding with their due dates."
method: POST
path: "/v1/reports/quarterly-package"
tags: ["Payroll & tax"]
---

# Quarterly estimated-tax package (Form 1040-ES): derives your current-year total tax (federal income + self-employment + FICA + state) from income, applies the safe harbor (lesser of 90% current or 100%/110% prior-year tax), and returns the four equal 2026 installments net of withholding with their due dates.

`POST /v1/reports/quarterly-package`

## Request

- Base URL: `` (relative, and it does not resolve against the document’s source URL)
- URL: `/v1/reports/quarterly-package`
- Auth: none declared

Quarterly estimated-tax package (Form 1040-ES): derives your current-year total tax (federal income + self-employment + FICA + state) from income, applies the safe harbor (lesser of 90% current or 100%/110% prior-year tax), and returns the four equal 2026 installments net of withholding with their due dates.

Payment: x402 ($1.00 USDC on eip155:8453). Call unpaid to receive an HTTP 402 with requirements, then retry with the PAYMENT-SIGNATURE header. Method: current-year tax composed from the verified tax-estimate engine, fed into the 1040-ES safe-harbor engine; four equal installments = (required - withholding) / 4

## Request body

- object
  - `filingStatus` 'single' | 'mfj'
  - `wages` number
  - `selfEmploymentIncome` number
  - `otherOrdinaryIncome` number
  - `adjustments` number
  - `deductionType` 'standard' | 'itemized'
  - `itemizedDeductions` number
  - `credits` number
  - `state` string
  - `priorYearTax` number
  - `priorYearAGI` number
  - `withholdingThisYear` number

## Response `200`

Verified result + provenance (formula, sources, reproducible SHA-256 hash).

## Other responses

- `400`: Invalid input (no charge) — body echoes the JSON Schema.
- `402`: Payment required — PAYMENT-REQUIRED header carries the x402 accepts[] quote.

---

[API](https://skmtc.dev/x402toll/apis/tollbooth-verified-calculators-for-ai-agents.md) · [All operations](https://skmtc.dev/x402toll/apis/tollbooth-verified-calculators-for-ai-agents/llms.txt) · [OpenAPI document](https://skmtc.dev/x402toll/apis/tollbooth-verified-calculators-for-ai-agents/revisions/60cb70a3e1a5?raw)