{"uid":"cap_cD_OCnnUIeqi1EU7jYrNw","slug":"x402toll-com-quarterly-estimated-tax-safe-harbor-calculator-5c0acacc","name":"x402toll.com Quarterly Estimated Tax Safe Harbor Calculator","description":"Quarterly estimated-tax safe harbor (Form 1040-ES): the required annual payment and per-quarter amount to avoid an underpayment penalty.","url":"https://x402toll.com/v1/tax/estimated","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"filingStatus":{"enum":["single","mfj","hoh","mfs"],"type":"string","default":"single"},"priorYearAGI":{"type":"number"},"priorYearTax":{"type":"number"},"expectedTaxThisYear":{"type":"number"},"withholdingThisYear":{"type":"number","default":0}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.1","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.1/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.1","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.1","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_HHwEzF3H6iNPe_Kq45mH7","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.1","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Computes the IRS Form 1040-ES safe harbor required annual payment and per-quarter estimated tax amount to avoid underpayment penalties.","exampleAgentPrompt":"I'm filing as married filing jointly. Last year my AGI was $185,000 and I paid $32,400 in federal income tax. This year I expect to owe about $38,000 and I'll have $12,000 withheld from my spouse's paycheck — what's the IRS safe harbor amount and how much should I pay each quarter to avoid an underpayment penalty?","exampleUseCases":null,"resultDescription":"Returns the IRS Form 1040-ES safe harbor required annual payment total and the corresponding per-quarter dollar amount the taxpayer must pay to avoid an underpayment penalty, based on the lesser of 100%/110% of prior year tax or 90% of current year expected tax.","failureModes":["Missing required fields (priorYearTax or priorYearAGI not provided) — returns validation error","Invalid filing status enum value — returns 400 bad request","Negative or implausible income values — may return computation error or unexpected results","Payment not processed (x402 payment required) — returns 402 Payment Required before computation"],"whenToPreferThis":"Use this endpoint when you need to compute the precise IRS safe harbor quarterly estimated tax payment amounts for a US individual taxpayer (Form 1040-ES), especially when you want to avoid underpayment penalties without overpaying. Prefer this over generic tax calculators when the specific need is safe harbor compliance rather than full tax return preparation.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-13T18:42:35.638Z","isFirstParty":false}