How to Pay International Vendors: Tax Forms, Methods, and Fees

Paying an international vendor from the United States is a five-part job: decide whether U.S. tax withholding applies, collect the right IRS form and banking details, screen the vendor against federal sanctions lists, send the money through a method that fits the payment, and file the annual reports the IRS expects. Skip any of these and you can end up personally liable for the tax you failed to withhold or facing per-form penalties that quickly outrun the invoice. Here is how to pay international vendors correctly, in the order the work actually happens.

Decide Whether U.S. Withholding Applies

The first question is not how to send the money. It is whether the payment is U.S.-source income in the eyes of the IRS. Personal service income is sourced to the place where the work is performed, not where the contract was signed, where the vendor lives, or where you send the funds.¹ A developer working entirely from Berlin earns foreign-source income, and payments to that vendor are generally outside U.S. withholding and outside Form 1042-S reporting.²

When a vendor works partly in the U.S. and partly abroad, allocate. The IRS uses a time-based split: multiply the payment by U.S. workdays divided by total workdays of service, and only the U.S.-source portion is subject to withholding.¹ Two weeks spent on-site at your office can turn a fully offshore engagement into a partially withholdable one.

Collect the Tax Form and Banking Details

The Right W-8

Before the first payment goes out, request the appropriate IRS form. For an individual foreign vendor, that is Form W-8BEN. For a foreign entity, it is Form W-8BEN-E.³ The form certifies the vendor’s foreign status and lets them claim a reduced withholding rate under any tax treaty their country has with the United States. Without a valid W-8 on file, you must withhold the full 30% on U.S.-source payments.⁴

Entities also need to declare a chapter 4 (FATCA) status on the W-8BEN-E. Failing to establish that status can trigger a separate 30% withholding on what the IRS calls withholdable payments, independent of the income-tax rules.⁵

Track expiration dates. A W-8BEN is generally valid from the date it is signed through the last day of the third full calendar year after signing, so one signed in June 2026 expires December 31, 2029. It expires immediately if the vendor’s circumstances change, for instance by becoming a U.S. resident, and the vendor is required to notify you within 30 days.⁶

Banking Coordinates

You will need two identifiers to route the payment. The first is the vendor’s Business Identifier Code, commonly called a SWIFT code, which identifies their bank under ISO standard 9362.⁷ The second is the vendor’s International Bank Account Number (IBAN), used in most countries outside the United States. An IBAN starts with a two-letter country code and two check digits, and its total length varies by country up to 34 characters.⁸ Ask the vendor to copy the IBAN directly from their bank’s system. A single wrong character can misdirect the wire, and reclamation fees are steep.

Screen the Vendor Against OFAC Sanctions

Every U.S. person, meaning citizens, permanent residents, U.S.-incorporated entities, and their foreign branches, must comply with sanctions administered by the Treasury Department’s Office of Foreign Assets Control.⁹ Transactions with anyone on the Specially Designated Nationals list are prohibited, and you are required to block any property in your possession in which an SDN has an interest.¹⁰

OFAC’s free Sanctions List Search tool at ofac.treasury.gov uses fuzzy-matching logic to catch close spelling variants of names.¹¹ Run every new vendor before the first payment, and re-run existing vendors on a schedule. Civil fines under the International Emergency Economic Powers Act can reach $377,700 per violation, and certain programs carry maximums above $1.8 million, with criminal penalties available on top.¹² Using a payment platform does not shift this obligation off you.

Pick a Payment Method

SWIFT Wire Transfers

SWIFT is the standard rail for large or time-sensitive international payments. The network does not move cash; it sends standardized instructions between banks that settle through existing credit relationships. Each wire is processed individually with a unique reference number, and funds typically arrive within one to two business days.¹³ When the sending and receiving banks do not have a direct relationship, the wire passes through one or more correspondent banks, each of which can add a fee and a bit of delay. Choosing a bank with strong correspondent coverage in the vendor’s region reduces both.

Global ACH

Global ACH extends the U.S. direct-deposit model into foreign clearinghouses. Transactions are batched rather than processed one by one, which makes ACH cheaper than a wire, often a few dollars instead of tens of dollars, and delivers funds in the vendor’s local currency. Settlement usually takes one to five business days, with three being typical. For recurring payments like monthly retainers, this is generally the better fit.

Digital Payment Platforms

Services like PayPal and Wise settle on their own ledgers rather than through banking rails. Both parties need accounts with the same provider, but exchange rates are often closer to mid-market than what banks quote. These platforms are practical for smaller payments and for vendors whose local bank does not comfortably receive international wires. Disputes go through the platform’s own process, and withdrawing to a local bank account can add its own fees and delay.

Understand the Fees Before You Send

International wire fees at major U.S. banks typically run $25 to $65 on the sending side. That is only your bank’s charge. Intermediary banks and the receiving bank may each take their own cut, and the total is hard to predict.

When you set up a wire, you have to choose a fee allocation code. The three options behave differently:

OUR means you pay all transfer fees, including intermediary charges, and the vendor receives the full invoiced amount.
SHA (shared) means you pay your bank’s outgoing fee and the vendor absorbs any intermediary or receiving-bank charges.
BEN (beneficiary) means the vendor pays every fee along the route, so they receive noticeably less than what you sent.

If your contract calls for a fixed amount and you pick SHA or BEN, expect a call from the vendor when a $5,000 invoice arrives as $4,955. When in doubt, use OUR and build the fee into your pricing.

Watch the exchange rate as well. Banks typically add a 1% to 3% margin over the mid-market rate when converting currencies. On a $50,000 payment, that spread alone costs $500 to $1,500. For recurring flows in the same currency, forward contracts or tighter-spread platforms can be worth pricing out.

File the Annual Tax Reports

Form 1042 and Form 1042-S

If you withheld tax on U.S.-source payments to foreign vendors during the year, you owe two filings. Form 1042-S reports each vendor’s income and the tax withheld. Form 1042 is the annual return that reconciles everything reported on your 1042-S forms. Both are due March 15 of the year after payment, with the deadline sliding to the next business day if March 15 falls on a weekend or holiday.¹⁴

The default withholding rate is 30% on U.S.-source income paid to foreign persons. A lower treaty rate applies only if you hold a valid W-8 supporting it.³ If you under-withhold, you become personally liable for the tax plus interest and penalties. “The vendor never sent me a W-8” is not a defense; the duty sits with the payer.

When 1099-NEC Applies Instead

Form 1099-NEC reports nonemployee compensation of $600 or more paid to U.S. persons, including U.S. citizens and resident aliens who happen to live abroad.¹⁵ It does not apply to nonresident aliens; payments to them belong on Form 1042-S.¹⁶ The shorthand: a W-8 on file means 1042-S; a W-9 means 1099-NEC.

E-Filing and Penalty Tiers

If you file 10 or more information returns of any type during the year, Form 1042-S must be e-filed. Financial institutions must e-file regardless of volume. For tax year 2026, the IRS Information Returns Intake System (IRIS) is the only accepted platform.¹⁴

Late or incorrect filings scale up quickly:

Filed within 30 days of the deadline: $60 per form, up to $698,500 per year ($244,500 for small businesses).
Filed after 30 days but by August 1: $130 per form, up to $2,095,500 per year ($698,500 for small businesses).
Filed after August 1 or not at all: $340 per form, up to $4,191,500 per year ($1,397,000 for small businesses).
Intentional disregard: the greater of $690 per form or 10% of the reportable amount, with no cap.

A separate penalty of up to $340 applies per form you fail to furnish to the recipient.¹⁴ Twenty missed vendor forms past the August 1 cutoff is $6,800 in filing-side penalties before you add the recipient-copy layer.

Execute the Transfer

With documentation collected, sanctions screening clear, and a method chosen, the mechanics are straightforward. In your bank’s international transfer portal, enter the IBAN and BIC, specify the payment currency, select the fee allocation code, and review the exchange rate the bank is quoting. The bank will show the total dollar cost including its FX margin and fees. Confirm and authorize.

The bank then issues a transaction reference. For SWIFT wires, this is an MT103 message, a standardized confirmation that records the sender, recipient, amount, and routing. Send the reference to the vendor so they can trace the incoming funds on their side, and keep a copy for reconciliation, especially when intermediary fees reduce the amount that arrives. If a payment does not land inside the expected window (two business days for wires, up to five for ACH), the MT103 reference is what your bank uses to locate where in the correspondent chain the funds are sitting.

1
Internal Revenue Service. Source of Income – Personal Service Income
2
Internal Revenue Service. Foreign Source Income – Form 1042-S Reporting Not Required
3
Internal Revenue Service. Instructions for the Requester of Forms W-8BEN, W-8BEN-E, W-8ECI, W-8EXP, and W-8IMY
4
Office of the Law Revision Counsel. 26 USC 1441 – Withholding of Tax on Nonresident Aliens
5
Internal Revenue Service. Instructions for Form W-8BEN-E
6
Internal Revenue Service. Instructions for Form W-8BEN
7
Swift. Business Identifier Code (BIC)
8
Swift. IBAN Registry
9
U.S. Department of the Treasury. OFAC FAQs – 11. Who Must Comply With OFAC Sanctions
10
U.S. Department of the Treasury. Specially Designated Nationals (SDNs) and the SDN List
11
U.S. Department of the Treasury. Sanctions List Search Tool
12
Federal Register. Inflation Adjustment of Civil Monetary Penalties
13
J.P. Morgan Payments Developer Portal. ACH vs. Wire Transfers and When To Use Each
14
Internal Revenue Service. Instructions for Form 1042-S (2026)
15
Internal Revenue Service. Instructions for Forms 1099-MISC and 1099-NEC
16
Internal Revenue Service. Reporting Payments to Independent Contractors