How TaxCrossing Helps AP and Tax Teams Get Withholding Right

October 17, 2026·6 min read·Guides

TaxCrossing applies IRS rules and US tax treaty text to the facts your team enters about a payment, and shows its reasoning. You answer the questions. The result names the treaty article or statute behind the rate, explains it in a sentence, and points to the form that would change it when one would. It supports the people who make the withholding decision, and leaves the decision with them.

The facts are yours: nothing counts until you have entered or confirmed it.

Every result shows its citation and a plain-English reason.

The reason is plain enough to share with the payee.

Each result shows what triggered withholding: the payment type, the sourcing rule, and the US-source share.

Teams that pay foreign contractors and licensors are often asked to trust a number they cannot check. This article explains what TaxCrossing does with your information, what it shows you, and where your team's judgment still sits, so you can decide whether it belongs in your process. For the steps themselves, in the order they are asked, see the sequence the tool runs. To compare it with other ways of handling withholding, see the buyer's guide to withholding tax software.

You control the facts

TaxCrossing asks for the facts of a payment rather than guessing them. Your team answers each question: who the payee is and what their W-8 says, where the work was performed or where the licensed property is used, what the payment is for, and whether a treaty is claimed. The rules are then applied to those answers.

Two features read documents and suggest answers, and your team confirms each one. Contract review reads an uploaded contract and proposes the payment type, the amount, and where services are performed. Each suggestion is marked as a suggestion and has to be confirmed, or changed, before the determination can run. The W-8 reviewer reads an uploaded form and shows what it found for your team to check before it is saved.

When a fact is missing, the result says so. If there is no valid W-8 on file, for example, the result does not assume one. It applies the IRS rule for undocumented payees and tells you which document would change the answer.

A tool for your team, not a replacement for it

TaxCrossing is built to support the judgment of AP and tax staff. Each determination is confirmed by someone on your team, and the confirmation is recorded with it. The audit memo carries a sign-off block for the reviewer's name, title, and date. When a payment raises a question that turns on facts the tool cannot see, such as whether a treaty definition reaches a particular service, the result says that professional review is recommended rather than presenting the answer as settled.

It is not legal or tax advice, and it does not say otherwise. What it gives your reviewer is the work laid out: the facts, the rule, the rate, and the reason, ready to be checked.

No black box: the rule behind every answer

Each result shows, on the screen:

The rate and the dollar amount to withhold.
A one-line reason, in plain English, naming the treaty and article or the statute that produced the rate.
The calculation: the payment, the US-source share, the rate applied to it, and the amount withheld.
Action items in plain terms, most with a "What to do" step.

The audit memo for the payment adds the full trail: the sourcing rule with its Internal Revenue Code section (for example, IRC §861(a)(4) for royalties), the 30% default rate under IRC §1441(a), the treaty and article applied, the regulations where they apply, and any audit notes. The memo and the screen are built from the same saved result.

An explanation you can give the payee

Payees often ask why money was held back. The one-line reason on each result is short and plain enough to share with the payee, or to put in your own words. It says what the rate is and why.

When a document or a line on a form is what stands between the payee and a lower rate, the reason says which one: a current W-8, the foreign tax identification number on the W-8, or the limitation-on-benefits certification on a W-8BEN-E, for example. When nothing the payee could sign would change the rate, because there is no treaty to claim, the reason says that too. Either way the payee hears the same reason your file records.

Seeing what triggers withholding

Every result shows what triggered the withholding: the payment type, the sourcing rule that applies to it, and the share of the payment that is US-source. Services performed in the US, and royalties or license fees for property used in the US, are US-source. Work performed entirely abroad is not, and nothing is withheld on it.

Contract review runs the same questions on a draft contract. Upload the agreement before it is signed, and your team can see whether the payment terms, as drafted, lead to withholding, while there is still time to talk about them.

On paid plans, the Annual WHT Summary export lists every payment for the year, for teams that want to review the year as a whole.

Worked example: two payments from the demo account

These are two determinations from TaxCrossing's demo account, which holds synthetic payees and no customer data.

A $60,000 software license fee to a Brazilian company, for software used in the US. The result shows the full $60,000 as US-source, because the software is used here. The rate is 30%, and $18,000 is withheld. The reason says the US has no income tax treaty with Brazil, so the statutory 30% under IRC §1441 applies and there is no treaty benefit to claim. That last clause is the one to pass to the payee: no form they could sign would lower this rate.
A $12,000 book royalty to an author in Spain, with 70% of sales in the US. The result splits the payment: $8,400 is US-source and $3,600 is not. The author's W-8BEN claims the US-Spain treaty, and the reason names its Royalties article (Article 12) as the source of a 0% rate. Nothing is withheld, and the US-source $8,400 still goes on a Form 1042-S at year end.

Each of the two results comes with the same audit memo, with the sourcing rule, the rate, and the citation set out for the file.

Why it matters

The payor is liable for withholding it should have made and did not (IRC §1461), so the reasoning behind every rate has to survive a question from an auditor, a CPA, or the payee. A tool that applies the rules to your own facts, shows the citation, and explains the answer in plain English gives your team something it can check and stand behind. Run one of your own payments and the determination comes out with the reason and the citation attached.

Working out what to withhold on a real payment right now?
The tool runs this exact sequence for one payment: who the payee is, where the work was done, what the treaty says. It returns the rate, the form, and the citation for the file.

Run the determination

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See how it works first

This article is general information for US withholding agents, not legal or tax advice. Treaty positions turn on the payee's specific facts and the current treaty text. Confirm the analysis for your situation with a qualified tax advisor before relying on it.

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