Multiple unexpected tax_lines on Order Line Items

Products and Orders APIs
1

Hi everyone,

We have an app that processes incoming webhooks for orders/paid. As part of its operation, the app examines the taxes applied to each line_item and shipping_line.

Recently, one merchant reported that our app was processing taxes incorrectly. During our investigation, we discovered that each line_item in the order contained multiple tax_lines. Notably, the first tax_line always has a rate of 0.0 and a price of 0.0.

"tax_lines": [
{
  "price": "0.00",
...
  "rate": 0.0,
  "title": "PT VAT"
},
{
  "price": "5.24",
...
  "rate": 0.22,
  "title": "PT VAT"
}]

From the merchant’s perspective, this situation is problematic—it should show either a 0.0 tax or a tax with a valid rate and amount, but not both.

Although our documentation states that multiple tax_lines are allowed (i.e., tax_lines: A list of tax line objects…), we still cannot determine why or how this is occurring. According to the tax laws under which we operate, this situation is not valid, so we’re unsure how to proceed.

I suspect that there may be a misconfiguration in the store’s settings, but I haven’t been able to identify the issue.

Has anyone encountered a similar situation? How would you configure taxes to result in this outcome?

Thanks in advance for your insights!