When non-US owners come to the US, they often learn the hard way about tax rules like FDAP income.
A US company holds back 30%. A bank needs a W-8 form. When the year ends, a Form 1042-S shows up. You suddenly have to pay US taxes, even though you don’t live or work in the US.
This piece talks about FDAP income, why it exists, how it works, and what non-US founders should be aware of.
What FDAP income is and why it causes confusion
You can get FDAP, which stands for Fixed, Determinable, Annual, or Periodical income. In real life, it means certain types of idle income from the US that is paid to people outside of the US.
FDAP is hard to understand because you don’t have to be in the US to use it. If you do business in the US but have never been there or have an office there, you can still cause FDAP. If the money comes from the US and is FDAP, the US usually taxes it by taking money out of the paycheck.
A lot of founders think that they only have to pay US taxes when they are “doing business” in the US. FDAP often surprises people by going against what they think.
Common FDAP income and what actually happens
FDAP usually includes passive payments like interest from US sources, dividends made by US companies, royalties for using IP in the US, and other similar payments.
The baseline rule is easy to understand when FDAP income is present. The person who is paying must take out 30% US tax at the source and send it straight to the IRS. The net amount, after taxes, is sent to the person outside the US.
This is why founders don’t always “do” something to make FDAP happen. Usually, a US company, a bank, or a website acts as the withholding agent and does the withholding for you.
This withholding is usually the last word, unless there is a tax deal or a way to get the money back.
FDAP vs ECI and why the difference matters
FDAP is often mixed up with Effectively Connected Income (ECI), but the two are taxed very differently.
Generally applies to passive US-source income and is taxed through withholding, usually without filing a US tax return. ECI, on the other hand, is income connected to a US trade or business and is taxed through a US return on a net basis.
For founders, the distinction matters because FDAP does not automatically mean you have created a US business presence. However, it still has real cash consequences because it is taxed on a gross basis, before expenses.
How FDAP affects non-US founders and the role of tax treaties
Depending on who gets the money, FDAP can have an effect on the leaders personally or on the business as a whole. A standard FDAP case is when a US C-Corporation pays dividends to a founder who is not US. Some types of income or royalties are also.
If a US tax deal is in place, the outcome can be very different. A lot of deals lower the 30% rate of default, sometimes by a lot. Depending on the contract and how the shares are owned, dividends could go down to 15%, 10%, 5%, or even 0%. A lot of the time, interest and fees are also cut.
But treaty perks aren’t always there. The withholding agent must use the lower rate and make sure the right paperwork is turned in. If that doesn’t happen, the payer will automatically take 30% out, even if there is a deal in place.
Forms and paperwork founders actually see
FDAP is heavily documentation-driven.
Non-US founders most commonly encounter Form W-8BEN (for individuals) or Form W-8BEN-E (for entities). These forms confirm non-US status and, if applicable, claim treaty benefits.
Forms 1042 and 1042-S are usually filed by the withholding agent, not by the founder. Founders typically become aware of FDAP when they receive a Form 1042-S showing the income paid and tax withheld.
Most problems arise not because founders do something wrong, but because documentation is missing, outdated, or misunderstood.
Can FDAP be refunded or avoided
In many situations, FDAP withholding is final. If no treaty applies, or if treaty benefits were not properly claimed, the 30% tax may simply be the cost of receiving that income.
In some cases, it is possible to recover withholding by filing a US tax return, but this is limited and often impractical. The process can be slow, documentation-heavy, and sometimes not worth the effort once professional fees are considered.
This is why FDAP planning is usually about avoiding unnecessary withholding upfront, rather than trying to fix it later.
Managing FDAP exposure in practice
For non-US founders, FDAP issues usually arise from a lack of visibility. Founders don’t realize a payment is US-source, don’t expect withholding, or assume someone else has handled it.
Managing FDAP properly means understanding how money flows, how payments are classified, and how treaties and documentation affect the outcome. Small structural choices can make a big difference.
How Neubase helps
When a client comes to Neubase, we talk to them about how money moves between the US company, its founders, and any non-US participants.
When it’s possible, we help founders set things up so that FDAP income doesn’t come in at all. If it’s not possible to avoid FDAP, we help make sure it’s done right and with the right paperwork so there are no problems later.
FDAP is not a big deal for owners who are non-US residents. But you should know about it early on, before it slowly drains your cash flow.
Final thoughts
When you understand one thing about FDAP, it’s not hard to understand the rest. If certain US-sourced income is paid to a non-US person, the US may automatically deduct 30% before you get the money.
You can start it even if you don’t live in the US. Withholding is put in place—often automatically—if the income comes from the US and fits the FDAP group.
Most problems are caused by information that is missing or wrong, not by something the founders did. With the right W-8 form and treaty claims, you can cut down on or get rid of needless withholding.
For owners who are not from the US, the goal is simple: know how money moves, know when FDAP applies, and take care of the paperwork early on. It is easier to plan ahead than to try to get money back after the fact.
