Form W-8BEN and the US Treaty: What Actually Gets Withheld

General information about tax rules, not tax or legal advice. Rules change and every situation is different: check with a qualified adviser in your country before you file.

Open an account with an American futures broker from Zagreb and you will reach a screen with Form W-8BEN on it. Two pages, mostly identification, one signature under penalties of perjury. In the middle of page one there is a box that asks you to certify that you are a resident of a country that has an income tax treaty in force with the United States, and then to write the name of that country.

A Croatian resident cannot honestly fill that box in. Not because of anything you did, and not because of anything your broker did, but because there is no income tax treaty in force between Croatia and the United States. Croatia is one of the very few European Union member states in that position, and it has been since independence.

That sounds like bad news and, for somebody holding American shares, it is. For somebody trading MES, MNQ or CL it matters far less than it looks, because the profits from closed futures positions are not the kind of income the withholding system was built to catch. This article explains the difference, what to do with Part II of the form, what the convention signed in 2022 would change if it ever enters into force, and what the Croatian tax administration expects when the money lands.

The box you cannot tick

Start with the fact, because there is a lot of confident nonsense about this in trading groups.

The IRS keeps a public list of the countries whose income tax treaties are in force, the United States income tax treaties from A to Z page. Work down the alphabet. Between the entries for the countries either side of it, there is no Croatia. Slovenia is there. Hungary is there with a warning attached. Croatia is simply absent, and has been absent for the whole period during which Croatian traders have had access to American brokers.

The practical consequence is short. Part II of the W-8BEN, lines 9 and 10, stays blank. You do not write Croatia on line 9. You do not write the European Union on line 9, which is a thing people genuinely try, and which is meaningless because treaties are bilateral. You do not borrow the treaty of a country where your broker happens to be incorporated. If there is no treaty, there is no treaty claim, and the statutory rates apply to anything that is actually subject to withholding.

What you absolutely do complete is Part I and Part III. That is the part of the form nobody should skip.

What Part I is doing for you

The full name of the document, as the IRS puts it on the page about Form W-8BEN, is Certificate of Foreign Status of Beneficial Owner for United States Tax Withholding and Reporting. The treaty claim is an optional extra bolted onto a form whose main job is something else entirely.

The main job is to establish that you are a foreign person and the beneficial owner of the money. That claim is worth having even with no treaty behind it, for two reasons.

First, without it the payer is left with presumptions, and the presumption rules exist to protect the US Treasury, not you. A payee who has not documented foreign status can be treated as a US person who has failed to certify a taxpayer identification number, which opens the door to backup withholding under the domestic rules. That is withholding applied to gross proceeds, not to profit, and on a futures account gross proceeds can be an enormous number relative to what you actually earned.

Second, the form is what lets the broker report you correctly at the end of the year. A documented foreign person with no US source reportable income gets a quiet year end. An undocumented one gets forms filed about them that they then have to explain.

The current revision is dated October 2021, and the instructions state the consequence of not filing it plainly: failure to provide a Form W-8BEN when requested may lead to withholding at the thirty per cent foreign person rate or to backup withholding.

What the thirty per cent actually reaches

American law divides what a non resident receives from the United States into two families, and only one of them is exposed to withholding at source.

One family is income effectively connected with a US trade or business, taxed on a net basis at graduated rates through a US return. The other is income that is fixed, determinable, annual or periodical, which the IRS shortens to FDAP, taxed at a flat thirty per cent with no deductions allowed, collected by the payer before the money moves.

FDAP is a list, not a mood. Dividends on US shares and US listed ETFs. Certain interest, though the domestic portfolio interest exemption clears most ordinary interest paid to non residents. Royalties. Certain pensions and annuities. If a Croatian resident holds a dividend paying American share, the absence of a treaty is felt immediately and in full: the statutory thirty per cent comes off the dividend, where a German or Slovenian resident with an identical position would see a reduced treaty rate.

This is the real cost of Croatia's position, and it is worth being precise about it. It is a cost on investment income. It is not a cost on speculation in futures.

Why futures gains escape anyway

The profit on a closed MNQ trade is not a dividend, not interest and not a royalty. It is a gain on the disposal of a contract, and gains live under a different regime.

Two mechanisms do the work, and neither of them depends on a treaty, which is exactly why the Croatian futures trader is in a much better position than the Croatian dividend investor.

The first is sourcing. For a non resident individual, a gain on the sale of personal property is generally sourced by reference to where the seller resides, not where the exchange sits. A trade matched in Chicago by a person sitting in Split produces a gain that is not US source. American withholding reaches US source income. If the income is not US source, there is nothing to withhold and therefore nothing for a treaty to reduce. The absence of a treaty is irrelevant in that scenario, which is the single most useful sentence in this article.

The second is the trade or business question. Trading for your own account through a US broker does not by itself make a non resident who is not a dealer into a person carrying on a trade or business in the United States. That safe harbour is why European retail traders can hold accounts in Chicago without acquiring an American filing obligation.

There is one exception worth naming out loud. A flat thirty per cent can be imposed on US source capital gains of a non resident individual who is physically present in the United States for one hundred and eighty three days or more in the tax year, and the IRS is explicit that this presence test is not the substantial presence test and can catch transactions carried out while you were not in the country. If you spend long stretches in the United States, the analysis changes and you need a US adviser, not an article.

The convention signed in 2022, and why it changes nothing yet

Croatia and the United States did negotiate. The US Treasury publishes documents on its tax treaties page, and the Treasury notes that treaties are posted there upon signature and prior to ratification and entry into force. A convention between the United States and Croatia with respect to taxes on income appears with a signature date of 7 December 2022, and a protocol amending it appears with a later signature date in 2026.

Signature is not the finish line. An American tax treaty needs the advice and consent of the Senate before ratification, and then both sides exchange instruments and the treaty enters into force on the terms it sets for itself, typically with different start dates for withholding taxes and for other taxes. The gap between signature and effect has run to years in the recent past, and one treaty signed in the last decade waited a very long time in the Senate before moving.

Until that process completes, the IRS list is the operative document, and Croatia is not on it. So the position for now is unchanged: blank Part II, statutory rates on FDAP, nothing to withhold on futures gains.

It is worth keeping an eye on, because the day it does enter into force, two things change for Croatian traders: dividends and interest from American sources become cheaper, and line 9 of the W-8BEN finally has a correct answer. At that point every Croatian client of every American broker will need to file a fresh form, because the one on file will not contain a treaty claim.

Filling the form in with an OIB

The lines that cause trouble for Croatian applicants are predictable.

Line	What a Croatian resident puts in it
1	Your full name as it appears in your passport, diacritics included or transliterated consistently. Pick one spelling and use it everywhere.
2	Country of citizenship, written out in full.
3	Your permanent residential address in Croatia. Not a post office box, not a business address you do not live at, and never an address in the United States.
5	US taxpayer identification number, only if you actually hold one. Most Croatian traders leave it blank.
6a	Your foreign tax identifying number, which in Croatia is the OIB, the eleven digit personal identification number.
8	Date of birth in the American order: month, day, year. Entering it the Croatian way is the most common single error on the form.
9	Leave blank. There is no treaty to certify residence under.
10	Leave blank.

Line 6a is not optional decoration. The instructions require a foreign tax identifying number where you hold an account with a US financial institution and receive US source income, unless your jurisdiction does not issue such numbers. Croatia issues the OIB to everybody, so there is no excuse available to you, and a form without it will come back.

And to say it once more, because somebody always tries: do not write anything in Part II. A treaty claim that does not exist is not a harmless optimism. It is a false certification signed under penalties of perjury, and the person who signed it is you, not the support agent who told you to.

What Porezna uprava expects at your end

Nothing about the American side removes the Croatian side. A Croatian tax resident is taxable on worldwide income, so profits made on an American platform are reportable in Croatia whether or not a cent was withheld in the United States.

The authority for all of this is Porezna uprava, the tax administration within the Ministry of Finance, which publishes the guidance on income tax, on reporting foreign income and on determining tax residence. If the day ever comes that you need to prove Croatian residence to an American payer, the residence certificate comes from there too, and it is not issued the same afternoon.

One more thing that applies whatever your treaty position. A signed W-8BEN generally stays valid from the date of signature until the last day of the third following calendar year, unless a change in circumstances makes the information on it wrong. Moving abroad is a change of circumstances. So is acquiring US person status, which would replace this whole analysis with a different one. The obligation to tell the payer is yours, normally within thirty days, and the most common trigger is the dullest: you move flat, the address no longer matches your bank records, and a routine review sits on a withdrawal for three weeks.

This article is general information about how the US withholding rules interact with a Croatian tax position, and it is not tax or legal advice. The rules change, treaties enter into force, and how your own trading is treated depends on facts that only a qualified Croatian adviser or Porezna uprava can assess for your case. Verify before you rely on any of it.

w-8ben croatia withholding

Educational content, not investment advice. Trading futures involves substantial risk of loss and is not suitable for every investor. Any reference to Algomyth results is hypothetical, simulated over historical data, and shown in full on the performance page; past performance does not guarantee future results.