The tax side of this is nontrivial.
You sound like you are doing this because you have problems extracting money from your customers. In other words, you have a business process problem. If at all possible I would suggest finding a business process solution to your business process problem.
Here's why. You are solving a business process problem with a legal solution. You are pounding nails with a screwdriver. It is going to create a tax problem for you.
A U.S. corporation (formed in Delaware or anywhere else) is a taxpayer. The Federal government will be looking for a tax return from this corporation. (Form 1120, if you want to look at it). Your money collected from your customers will be flowing into that corporation. That looks like taxable income to the U.S. government.
Now you have replaced your business process problem with a U.S. government tax problem. That's an order of magnitude worse. You can solve tax problems, but it takes time and money to do so. That means lawyers and accountants and paperwork.
So now you have replaced your business process problem with a tax problem, and you have solved your tax problem with an "accountants and lawyers and paperwork and overhead and brain damage" solution.
Is it cost-effective? Maybe.
Then the next thing to consider is State income tax. The U.S. has a peculiar set-up for income tax. The Federal government imposes an income tax. Most of the States impose an income tax. Some cities also impose an income tax (stay the F away from Philadelphia and New York, for instance).
Your Delaware corporation must be doing business SOMEWHERE. "Must be somewhere, can't be nowhere." So you need a physical presence somewhere for your corporation, even if it is only a glorified Post Office Box. You put that in a tax-free location. More money.
In summary: sub-optimal.
OK. If you absolutely have to solve a business process problem with a legal solution, look at this as a possible solution:
1. Check with your tax advisor in Portugal. What type of entity is your company? You want it to be taxed as a corporation as defined in U.S. law. THIS IS ABSOLUTELY ESSENTIAL. (It doesn't matter how your company is taxed in Portugal. We're doing U.S. tax engineering here).
2. Form a Delaware limited liability company. If necessary, file Form 8832 to have the LLC treated as a disregarded entity.
3. Get your authorize.net or whatever account in the name of the Delaware LLC.
4. <the moment of magic> I don't know if this will work or not but if it does, then you win. You want the Delaware LLC to NOT be a "permanent establishment" of your Portuguese corporation as that phrase is defined in the income tax treaty between Portugal and the United States. See Article 5 of the Treaty if you want to be confused. :-)
5. The impact of NOT having a permanent establishment in the USA? Only Portugal can tax your profits. The USA cannot tax your profits even though they are earned in the USA.
6. The objective you are aiming for is this:
- you have a Portuguese corporation deriving profit from U.S. sources.
- The money pipelines through a Delaware LLC which is disregarded for tax purposes, so it is as if the Portuguese corporation is doing business directly in the USA for tax purposes.
7. You file Form 1120-F for the Portuguese corporation, and attach Form 8833 claiming the benefits of the treaty.
- By doing this you are saying to the U.S. tax authorities: "Yes, I have U.S.-source profits but the U.S. can only tax those profits if they are derived from a permanent establishment in the USA and my Portuguese corporation does not have a permanent establishment in the USA. So go bite tires."
That's what I would do.
(I do this in real life but I am not your lawyer, this is not legal advice, you'd be a damn fool to rely on random postings on a website to make critical financial and business decisions, etc. etc.)
Phil.