Complete Draft Rules Re: UBL 2 Invoice Calculation Model

[Stephen Green <stephengreenubl@gmail.com>]

Substantive Completion of Draft 2 of UBL 2 Invoice Calculation Model Rules


The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL
      NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED",  "MAY", and
      "OPTIONAL" in this document are to be interpreted as described in
      RFC 2119.
http://www.ietf.org/rfc/rfc2119.txt


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U2ICMDraft2Rule1:

"To be a conforming UBL 2 invoice the document MUST be valid according
to a standard UBL 2 Invoice schema."

U2ICMDraft2Rule2:

"The document level line extension total SHOULD be the sum of all line
extension amounts at line level."

U2ICMDraft2Rule3:

"The 'TaxExclusiveAmount' in the invoice 'LegalMonetaryTotal' SHOULD
be equal to the sum of the 'LineExtensionAmount's in all of the
invoice lines plus the sum of the invoice 'AllowanceCharge' charges
minus the sum of the invoice 'AllowanceCharge' allowances."

U2ICMDraft2Rule4:

"The 'AllowanceTotalAmount' in the invoice 'LegalMonetaryTotal' SHOULD
be equal to the the sum of the invoice 'AllowanceCharge' allowances."

U2ICMDraft2Rule5:

"The 'ChargeTotalAmount' in the invoice 'LegalMonetaryTotal' SHOULD
be equal to the the sum of the invoice 'AllowanceCharge' charges."

U2ICMDraft2Rule6:

"In the invoice 'LegalMonetaryTotal' the 'LineExtensionAmount' SHOULD
be equal to the 'TaxExclusiveAmount' plus any 'AllowanceTotalAmount'
minus any 'ChargeTotalAmount'."

U2ICMDraft2Rule7:

"The 'TaxInclusiveAmount' in the invoice 'LegalMonetaryTotal' SHOULD be
equal to the TaxExclusiveAmount (in the invoice 'LegalMonetaryTotal')
plus the sum of the invoice total tax amounts (at invoice document
level)."

U2ICMDraft2Rule8:

"The 'PayableAmount' in the invoice 'LegalMonetaryTotal' SHOULD be
equal to the 'TaxInclusiveAmount' (in the invoice 'LegalMonetaryTotal')
plus the sum of any 'PrepaidPayment' amounts (at invoice document level)."

U2ICMDraft2Rule9:

"The sum of invoice document level tax total amounts SHOULD equal the sum of
all document level subtotal tax amounts."

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I'd make a suggestion that these might, subject to revisions and approval or
otherwise by UBL TC, be made normative rules, perhaps as part of UBL 2.1
(keyword 'SHOULD' allowing for exceptions due to corner cases such as
customisation removing an optional amount which is part of one of the rules).

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Stephen D Green