Form W-8IMY is the certificate a foreign intermediary, foreign flow-through entity or certain U.S. branch gives a U.S. withholding agent when it receives a payment on behalf of other people rather than for itself. Foreign partnerships, foreign simple and grantor trusts, qualified intermediaries and nonqualified intermediaries are the usual users.
This guide follows the IRS Instructions for Form W-8IMY (Rev. October 2021), the current revision as of October 2026.
Why the form exists
Foreign persons are generally taxed at a 30% rate on U.S. source income such as interest, dividends, rents and other fixed or determinable annual or periodical income, usually collected by withholding. A separate 30% withholding regime under chapter 4 (FATCA) applies to certain payments to foreign financial institutions and other foreign entities. When a payment passes through an intermediary or a partnership, the payer needs to know who's really behind it. W-8IMY is how the middle layer says, "I'm not the owner, here's who is."
Who gives a Form W-8IMY
| Entity | Why it uses W-8IMY |
|---|---|
| Qualified intermediary (QI) | To show it isn't acting for its own account and to say whether it assumes primary withholding responsibility |
| Nonqualified intermediary (NQI) | To pass along its customers' withholding certificates and a withholding statement |
| Foreign partnership, foreign simple trust, foreign grantor trust | As a flow-through entity, transmitting its owners' documentation |
| Certain U.S. branches of foreign banks or insurers | To agree to be treated as a U.S. person, or to transmit the documentation of the people it receives payments for |
| Territory financial institutions | To be treated as a U.S. person or to pass on documentation |
| QI acting as a qualified derivatives dealer (QDD) | To certify that status and, where it applies, claim treaty benefits |
When you shouldn't use W-8IMY
This is where most mix-ups happen. The instructions list the cases that need a different form:
- You're the beneficial owner of the income and want to prove foreign status or claim a treaty rate on your own behalf: use Form W-8BEN or Form W-8BEN-E.
- You're a hybrid entity claiming treaty benefits for yourself: use W-8BEN-E.
- The income is effectively connected with a U.S. trade or business and you own it: use Form W-8ECI.
- You're a nonresident alien individual claiming exemption on pay for personal services: use Form 8233 or Form W-4.
- You're a disregarded entity: your single owner gives the right W-8 for its own status instead.
The insight: W-8IMY rarely travels alone
A W-8IMY on its own usually isn't enough. Depending on the Part you complete, it goes with a withholding statement allocating the payment, plus the W-8 or W-9 forms of the partners, beneficiaries or customers behind it. The instructions are explicit that the form's open-ended validity doesn't extend to those attached certificates, statements or documents. A partnership can keep the same W-8IMY for years and still fail because one partner's W-8BEN has expired.
How long a W-8IMY stays valid
Generally a Form W-8IMY remains valid until the status of the entity named on it changes, or circumstances change so that the information is no longer correct. If that happens, you must notify the withholding agent within 30 days of the change in circumstances. Give the form before income is paid or credited, and send a separate form to each withholding agent that pays you.
If you don't provide it, the withholding agent may have to withhold at the 30% rate, apply backup withholding, or withhold under section 1446 on a foreign partner's share of effectively connected income.
Partnership transfers and section 1446(f)
Under section 1446(f), a buyer of an interest in a partnership from a non-U.S. seller generally has to withhold 10% of the amount realized if any of the gain would be effectively connected. The rules for brokers handling transfers of interests in publicly traded partnerships apply to transfers and distributions on or after January 1, 2023. Qualified intermediaries and certain U.S. branches use W-8IMY to take on that withholding or to supply the required statements.
A map of the form
| Part | For |
|---|---|
| Part I | Identification of the entity, its chapter 3 and chapter 4 status |
| Part III | Qualified intermediaries |
| Part IV | Nonqualified intermediaries |
| Part V and Part VI | Territory financial institutions and certain U.S. branches |
| Part VII and Part VIII | Withholding and nonwithholding foreign partnerships and trusts |
| Parts IX to XXVIII | Chapter 4 statuses such as active and passive NFFEs |
| Part XXIX | Certification and signature |
Payments documented with a W-8IMY often end up reported on Form 1042-S by the withholding agent, so the details you give here flow straight into that slip.
Before you sign it
- Confirm you're receiving the payment for others, or as a flow-through, and not as the owner.
- Pick the one Part that matches your chapter 3 role, then check whether the payment is withholdable under chapter 4 and you need a chapter 4 status in Part I.
- Collect current W-8 or W-9 forms from every owner or customer you're passing through.
- Prepare the withholding statement that allocates the payment among them, where your Part requires one.
- Diary a review, so a change in your status or an owner's status reaches the payer within 30 days.
The instructions also allow electronic signatures on withholding certificates under the chapter 3 regulations, which helps funds with many investors keep paperwork moving.
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The verdict
If you're a foreign fund, partnership or trust receiving U.S. income for other people, W-8IMY is your form, but only alongside a clean withholding statement and current owner certificates. If the income is yours, it's the wrong form and the payer may withhold the full 30%. Check which side of that line you sit on before you fill in a single box.
Frequently asked questions
What is Form W-8IMY used for?
It certifies to a U.S. withholding agent that you're a foreign intermediary, foreign flow-through entity or certain U.S. branch receiving payments on behalf of others, not as the beneficial owner.
What is the difference between W-8IMY and W-8BEN-E?
W-8BEN-E is for a foreign entity that's the beneficial owner of the income. W-8IMY is for an entity acting as an intermediary or flow-through for other people.
Does Form W-8IMY expire?
Generally it stays valid until a change in circumstances makes it incorrect, but that indefinite validity doesn't extend to the withholding certificates or statements attached to it.
How quickly must I report a change on a W-8IMY?
You must notify the withholding agent within 30 days of the change in circumstances.
Does a foreign partnership use W-8IMY?
Yes. A foreign partnership acting as a flow-through entity uses it to transmit its partners' documentation, unless it's claiming treaty benefits on its own behalf as a hybrid entity.
What happens if I don't give a W-8IMY?
The withholding agent may have to withhold at the 30% rate, apply backup withholding, or withhold under section 1446.
