How to pay US taxes from India: EFTPS, wires and estimated payments

Indian founders running US C-Corps face a payment-mechanics problem that nobody warned them about: how to actually get USD from India to the IRS and state tax authorities. The IRS does not accept Indian credit cards reliably, ACH requires US bank routing, and wire transfers need careful coding. The solutions are EFTPS enrollment through your US bank, wire transfers with correct reference data, and using the US business bank account (Mercury, Brex) as the payment rail. Estimated taxes are due quarterly for corporations with projected tax above USD 500.

EFTPS (Electronic Federal Tax Payment System) is the IRS's electronic payment system for federal taxes. Enrollment requires EIN, business name and address, and US bank account routing and account numbers. After enrollment (typically 7-10 business days for the PIN to arrive at the registered address), schedule payments online or by phone, up to 365 days in advance. EFTPS is the cleanest channel for US C-Corps paying estimated taxes (Form 1120-W), federal income tax, employment taxes (Forms 941, 940) and excise taxes. The US bank must be the C-Corp's account, not a personal account.

Corporations expecting to owe USD 500 or more in federal tax must pay quarterly estimated taxes. Due dates: 15 April (Q1), 15 June (Q2), 15 September (Q3), 15 December (Q4). Calculate using one of: (a) 100% of prior-year tax (safe harbour for corporations with prior-year tax under USD 1 million), or (b) 100% of current-year projected tax. Compute on Form 1120-W (worksheet, not filed with IRS). Underpayment triggers Section 6655 penalties. Pay via EFTPS. For state estimated taxes, each state has its own due dates and forms (e.g., California Form 100-ES).

If EFTPS enrollment is delayed or fails, wire transfer to the IRS works but requires the right reference data. Use the IRS wire transfer instructions for foreign-source payments (use SWIFT codes per IRS Publication 4990). The wire reference must include EIN, tax form (e.g., 1120), tax period (e.g., 202512 for December 2025) and payment type code. Without the right reference, the IRS cannot apply the payment and your account shows underpayment. Wire transfers from Mercury or Brex to the IRS Treasury account take 1-2 business days; build buffer time before the due date.

Each state has its own payment portal. California uses Web Pay through FTB.ca.gov; New York uses Online Services through tax.ny.gov; Delaware has Franchise Tax payments through the Division of Corporations site. Delaware franchise tax for C-Corps is due 1 March annually (minimum USD 175, up to USD 200,000 depending on shares method). California minimum franchise tax of USD 800 applies even with no income. Build a tax-payment calendar covering federal estimates (4 dates), state estimates (varies), franchise tax (varies), federal income tax (Form 1120 due 15 April for calendar-year corps), and state income tax.

Can I pay US taxes by Indian credit card?
Some IRS-approved payment processors accept Indian-issued cards, but fees are high (1.85-3% surcharge) and rejections are common due to fraud screening. Use only for one-off payments. For recurring payments, EFTPS from a US bank account is more reliable and free.

What is the deadline for Form 1120?
Calendar-year C-Corps file Form 1120 by 15 April of the following year (extended deadline 15 October with Form 7004 extension). Fiscal-year corporations file by the 15th day of the 4th month after fiscal year-end. Form 5472 (for foreign-owned C-Corps) is filed with Form 1120.

Do I need to make quarterly estimates if my first year has no profit?
Quarterly estimates are based on expected tax liability. If you expect no tax owed for the year, no estimates are required. But if profits arrive unexpectedly in Q3 or Q4, the safe harbour may have lapsed and underpayment penalties accrue. Estimate conservatively.

How long does EFTPS enrollment take?
7-10 business days for the PIN to arrive at the registered address by mail. Plan ahead - do not wait until 14 April to enrol for the 15 April quarterly. Many foreign founders use a US mail-forwarding service for the PIN delivery.

Can the IRS payment be reversed if I overpay?
Yes, overpayments are refunded after filing Form 1120 showing the overpayment, or applied to the next year's estimated tax. Refunds to foreign-address corporations take longer than to US-address ones - plan for 8-12 weeks.

Does the India-US treaty help reduce US C-Corp tax?
The treaty does not reduce the US C-Corp's federal income tax. It primarily helps with: cross-border withholding on payments between the C-Corp and its Indian shareholders or affiliates, and FTC claims at the shareholder level. The C-Corp itself pays full 21% federal corporate tax.