Form W-8BEN for New Zealand investors: 15% instead of 30% on US dividends

If you hold US shares or US-listed ETFs, the W-8BEN is the US form that gets your dividend withholding down from 30% to 15%. It certifies that you are not a US person and that you are a resident of New Zealand for treaty purposes. You give it to your broker or the payer, not to the IRS (IRS Instructions for Form W-8BEN). It matters for New Zealand tax because Inland Revenue only credits US tax up to the 15% treaty rate (IR461 p20). This guide explains what the form does, what to fill in and how long it lasts.

What the W-8BEN does

Form W-8BEN is a US Internal Revenue Service form for individuals who are not US persons and who receive US income that is subject to withholding. It does two things:

• Part I certifies that you are a foreign person (for the US) and the beneficial owner of the income.
• Part II claims the benefits of a tax treaty: for you, the New Zealand and United States income tax treaty.

The treaty, as amended by the protocol signed in 2008, says US tax on dividends paid to a New Zealand resident beneficial owner “shall not exceed” 15% of the gross dividend, or 5% for a company owning at least 10% of the voting power (Article 10(2), US Treasury copy of the protocol). Without the form, the IRS warns that you may be withheld at “the foreign-person withholding rate of 30%” (IRS Instructions for Form W-8BEN).

The IRS is clear that you “must give Form W-8BEN to the withholding agent or payer” and “Do not send Form W-8BEN to the IRS”. For most New Zealand investors the withholding agent is the broker or platform that holds the US shares. Many platforms collect the form online during sign-up; Stake describes automated W-8BEN forms (single platform source).

What it is worth

On every US$1,000 of US dividends:

New Zealand credits foreign tax only up to the rate allowed by the double tax agreement (IR461 p20). So the extra 15% taken without a W-8BEN is not just a timing difference; it is a cost, unless you recover it from the US. IR461’s Swiss example says over-withheld tax is something to ask the foreign tax authority for.

Example: under the $50,000 threshold

Below the threshold, your US dividends are taxed in New Zealand as ordinary income. Say you received $1,200 (NZ$) of gross US dividends and your other income is $70,000, so the dividends fall in the 30% band.

With the form, you pay tax once at your New Zealand rate, split between the two countries. Without it, you pay $180 more. Our dividends tool estimates 15% with a W-8BEN and 30% without when you leave the tax figure blank.

Example: over the threshold on FDR

Over $50,000, your FIF income is worked out by formula, and the dividends are not taxed separately (IR3G p21). The W-8BEN does not change your FIF income at all. It only changes how much US tax comes off the dividends, and the credit is still capped at 15%.

Say a US ETF worth NZ$100,000 on 1 April gives FDR income of $5,000 and pays $2,000 of gross dividends, and your other income is $95,000. The New Zealand tax on that holding’s FIF income is well above the treaty cap, so:

• with a W-8BEN, $300 is withheld and the whole $300 is credited;
• without one, $600 is withheld, $300 is credited, and $300 is lost.

The credit is also capped at the New Zealand tax on that holding’s FIF income, which can matter in a low CV year. The foreign tax credits guide works through that case.

Filling it in

The IRS instructions describe these lines:

Part III is the signature and date. If your platform collects the form online, check the details it shows, especially your residence country and address.

How long it lasts, and when to update it

A W-8BEN generally stays in effect until “the last day of the third succeeding calendar year” after it is signed, unless circumstances change (IRS instructions). A form signed on 12 November 2026 would therefore run until 31 December 2029. Once it expires you need to give a new one, or the payer may withhold at the 30% rate again.

If something on the form becomes incorrect, for example you move country, the IRS says you must notify the withholding agent “within 30 days of the change in circumstances” and give a new form.

A quick check: look at the dividend statements for your US holdings. If tax withheld is about 15% of the gross dividend, the form is working. If it is about 30%, contact your platform.

A short checklist

1. Confirm you are not a US citizen or other US person; if you are, the W-8BEN is the wrong form.
2. Check that each platform holding US shares for you has a current W-8BEN, and note when it expires.
3. Look at a recent US dividend: tax of about 15% means the treaty rate is being applied.
4. If the rate is about 30%, contact the platform and give it a form.
5. Give a new form within 30 days if your residence or other details change (IRS).
6. When you file, put the gross dividend or your FIF income in box 17B and only the creditable tax in box 17A (how to file).

Who should not use it

The W-8BEN is only for people who are not US persons. The IRS says not to use it if you are a US citizen (including one living abroad) or another US person such as a resident alien, and to use Form W-9 instead. US citizens living in New Zealand face both tax systems; New Zealand has special rules for people taxed on citizenship grounds, including the extended revenue account method (IR461 p17). See the revenue account method guide and the US retirement accounts guide, and get advice that covers both countries.

The W-8BEN is the form for individuals. If you hold US shares through a company or trust, ask your platform or adviser which form applies; we do not cover that here.

What it does not change

• It does not change whether you are in the FIF rules. That depends on the cost of your holdings (threshold checker).
• It does not change FDR or CV income.
• It does not remove the need to report the dividends and the tax in boxes 17B and 17A of your IR3 and on the IR1261 (how to file).

Rules checked 12 November 2026. General information, not tax advice; check with your accountant.

Questions

Do I send my W-8BEN to the IRS?

No. The IRS says to give it to the withholding agent or payer, which is usually your broker or platform, and not to send it to the IRS.

How long does a W-8BEN last?

Generally until the last day of the third calendar year after the year you sign it, unless your circumstances change (IRS instructions).

Can I claim the extra 15% back from Inland Revenue?

No. New Zealand only credits foreign tax up to the treaty rate, 15% for US dividends (IR461 p20). Any excess has to be recovered from the US.

Does a W-8BEN reduce my FIF income?

No. FIF income comes from FDR or CV. The form only changes the US tax taken from your dividends.