Missing tax registration ID scheme identifier

Error FX-SCH-A-000726 Factur-X

Attribute '@schemeID' is required in this context.

Mandatory rule: As long as it is violated, the invoice is invalid and will be rejected by validators.
What is wrong

The schemeID attribute is missing from ram:ID. As a result, the identification scheme used is not specified.

What the rule means

The schemeID attribute identifies the scheme used to interpret the value in ram:ID.

Please identify the product end user's tax registration ID scheme

The ram:ID in the tax registration is missing the attribute that identifies its scheme. Add the schemeID attribute.

What to do
  1. Locate ram:ID in the product end user's tax registration.
  2. Add the schemeID attribute to the element.
  3. Generate the invoice again and validate it.
What it looks like
✗ Triggers the message 
<ram:SpecifiedTaxRegistration>
  <ram:ID>123</ram:ID>
</ram:SpecifiedTaxRegistration>
✓ Correct 
<ram:SpecifiedTaxRegistration>
  <ram:ID schemeID="value">123</ram:ID>
</ram:SpecifiedTaxRegistration>
Technical details

The check requires the schemeID attribute to be present on ram:ID.

Where the rule applies

The rule applies to the schemeID attribute on ram:ID in the product end user's tax registration.

Context (rule/@context)
/rsm:CrossIndustryInvoice/rsm:SupplyChainTradeTransaction/ram:ApplicableHeaderTradeAgreement/ ram:ProductEndUserTradeParty/ram:SpecifiedTaxRegistration/ram:ID
Test expression (assert/@test)
@schemeID