Why the confusion exists
Both VAT and withholding tax can affect a cross-border invoice. Both involve a percentage deduction. Both are called "tax." But they arise from entirely different legal bases, apply to different taxable events, and are administered through different systems. The confusion comes from the fact that they can appear on or affect the same payment.
A Dutch designer invoices a Spanish company for €10,000. The Spanish company pays only €8,100 — they deducted something. Was it VAT? Withholding tax? Both? The answer determines what you report, what you can recover, and whether you have a problem.
This guide explains the distinction so you can identify which tax applies to your situation and respond correctly.