KB-354 — Cash Basis VAT Technical Validation¶

Version: 1.0
Status: Approved
Author: BLACK ERP Engineering
Category: Technical Accounting Certification

Purpose¶

This document defines the technical validation methodology used to certify the Cash Basis VAT implementation in BLACK ERP.

Unlike functional validation, which verifies accounting behavior through ERP documents and accounting windows, this document demonstrates that VAT accounting is correctly persisted inside FACT_ACCT.

The objective is to prove that VAT recognition follows the Mexican Cash Basis model from the database perspective.

Scope¶

This validation covers:

Purchase Cycle
Sales Cycle
Payment Allocation
Customer Allocation
FACT_ACCT
SQL Validation

Functional Overview¶

Mexican Cash Basis VAT requires that VAT is not recognized at invoice time.

Instead, VAT becomes deductible or payable only after the corresponding payment has been effectively applied.

BLACK ERP implements this behavior through Payment Allocation.

Purchase Validation¶

Functional Flow¶

Purchase Invoice

↓

Payment

↓

Payment Allocation

↓

Bank Reconciliation

Expected Accounting Flow¶

Invoice

119.001

VAT Pending Payment

↓

Allocation

118.001

VAT Paid

SQL Validation¶

Invoice

SELECT ...
FROM fact_acct
WHERE ...

Expected Result

Account	Debit	Credit
119.001	16.00	0.00

Allocation

Expected Result

Account	Debit	Credit
118.001	16.00	0.00
119.001	0.00	16.00

Technical Conclusion¶

The certification confirmed that:

Invoice

↓

119.001

↓

Allocation

↓

118.001

The VAT reclassification occurs only during Payment Allocation.

Sales Validation¶

Functional Flow¶

Sales Invoice

↓

Customer Payment

↓

Payment Allocation

↓

Bank Reconciliation

Expected Accounting Flow¶

Invoice

209.001

VAT Not Collected

↓

Allocation

208.001

VAT Collected

SQL Validation¶

Invoice

Expected Result

Account	Debit	Credit
209.001	0.00	28.80

Allocation

Expected Result

Account	Debit	Credit
209.001	28.80	0.00
208.001	0.00	28.80

Technical Conclusion¶

The accounting engine correctly postpones VAT recognition until the allocation process.

The database validation confirmed that VAT is reclassified exactly as required by Mexican Cash Basis legislation.

Database Evidence¶

During certification the following database validations were completed.

Purchase

✓ FACT_ACCT validated

✓ SQL validated

✓ Accounting Information validated

✓ Allocation validated

✓ Bank Reconciliation validated

Sales

✓ FACT_ACCT validated

✓ SQL validated

✓ Accounting Information validated

✓ Allocation validated

✓ Bank Reconciliation validated

Accounting Timeline¶

Purchases

Invoice

119.001

        │

Payment

(No VAT Change)

        │

Allocation

118.001

        │

Bank Reconciliation

(No VAT Change)

Sales

Invoice

209.001

        │

Customer Payment

(No VAT Change)

        │

Allocation

208.001

        │

Bank Reconciliation

(No VAT Change)

Accounting Events¶

Document	VAT Impact
Invoice	Creates Pending VAT
Payment	No VAT Impact
Allocation	VAT Reclassification
Bank Statement	No VAT Impact

Certification Result¶

Purchases

Validation	Status
Functional	✓
Accounting	✓
SQL	✓
FACT_ACCT	✓

Sales

Validation	Status
Functional	✓
Accounting	✓
SQL	✓
FACT_ACCT	✓

Final Conclusion¶

The BLACK ERP Cash Basis VAT implementation has been successfully validated at three independent levels.

• Functional Validation

• Accounting Validation

• Technical Database Validation

The SQL evidence obtained directly from FACT_ACCT demonstrates that VAT is recognized only during the Allocation process.

Therefore, the implementation complies with the expected accounting behavior for Mexican Cash Basis VAT.