NF525 compliant fiscal data protection for Openpos

1. Introduction

The WooCommerce Openpos NF525 Compliance Plugin is designed to help merchants comply with the French fiscal regulation NF525 for Openpos, as required by article 286-I-3 bis of the French General Tax Code.

The plugin ensures that sales data recorded in WooCommerce is:

• Inalterable
• Secured
• Conserved
• Archived

This plugin is suitable for WooCommerce version 10.4.3 and later.

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2. Who Needs This Plugin?

You need NF525 compliance if you using OPENPOS plugin and:

• Sell to individual customers (B2C) in France
• Accept cash, card, or electronic payments
• Are subject to French VAT (TVA)

Typical use cases:

• WooCommerce + POS
• WooCommerce with in-store pickup
• WooCommerce used as a cash register

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3. What the Plugin Does

Core Features

• Automatically seals each receipt after checkout
• Prevents modification or deletion of fiscal data
• Creates a hash chain to detect tampering
• Handles Cancel and Refund operations correctly
• Provides exportable fiscal data for audits
• Supports long-term data conservation (6 years)

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4. NF525 Principles Implemented

NF525 Principle	How the Plugin Implements It
Inalterability	Sealed orders cannot be edited
Securing	SHA256 hash chain
Conservation	Data stored permanently in database
Archiving	Period-based closing (monthly)

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5. Installation

1. Download the plugin ZIP file
2. Go to WordPress Admin → Plugins → Add New
3. Click Upload Plugin
4. Upload woocommerce-openpos-nf525.zip
5. Activate the plugin

⚠️ WooCommerce must be active before activating this plugin.

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6. How Receipts Are Created

Normal Sales

• When an order is completed, the plugin:
  • Assigns a unique sequential number
  • Generates a cryptographic hash
  • Seals the order (cannot be edited)

Cancelled Orders

• If an order is cancelled:
  • A CANCEL receipt is generated
  • Original data remains unchanged
  • Amount is recorded as zero

Refunds

• When a refund is issued:
  • A REFUND receipt is created
  • A new sequence number and hash are generated
  • The refund receipt is linked to the original order
  • Amount is recorded as negative

❗ The original receipt is never modified.

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7. Order Locking (Inalterability)

Once a receipt is sealed:

• Order totals cannot be changed
• Items cannot be edited
• The order cannot be deleted

This ensures compliance with NF525 inalterability requirements.

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8. Fiscal Data Export (Audit Use)

How to Export

1. Go to WooCommerce → NF525
2. Click Export fiscal data
3. A CSV file will be downloaded

Export Contents

The export file includes:

• Receipt sequence number
• Receipt type (NORMAL / CANCEL / REFUND)
• Order ID
• Parent order ID (for refunds)
• Date and time
• Amount and tax
• Cryptographic hash

This file can be provided directly to:

• French tax authorities (DGFiP)
• External auditors
• Accounting firms

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9. Archiving and Data Retention

• Fiscal data must be conserved for at least 6 years
• Monthly archiving can be performed to:
  • Freeze a period
  • Calculate an archive hash
  • Prepare data for audits

Archived data must not be altered.