VAT OSS Autopilot — Complete guide

Overview

VAT OSS Autopilot automates intra-EU VAT management for your WooCommerce store: real-time destination-country rate calculation, VIES validation of B2B VAT numbers with reverse charge, quarterly OSS return generation (summary CSV, detailed CSV, DGFiP XML) and fully configurable revenue threshold monitoring.

Requirements

• WordPress 6.2 or higher
• WooCommerce 7.0 or higher (tested up to 9.4)
• PHP 7.4 minimum (compatible 8.0 to 8.3)
• PHP extensions: SOAP (VIES validation), DOM (XML export), ZipArchive (ZIP bundle)
• WooCommerce taxes must be enabled (WooCommerce → Settings → General → Enable taxes)

Installation

1. Download vat-oss-autopilot.zip from your DataFirefly account.
2. In WordPress admin, go to Plugins → Add New → Upload Plugin.
3. Select the ZIP, click Install Now, then Activate.
4. A new VAT OSS menu appears in the admin sidebar.

On activation, the plugin creates the wp_vat_oss_sales table (OSS sales tracking) and pre-fills three French example thresholds, freely editable or removable.

Initial configuration

1. Tax identification

Go to VAT OSS → Settings and fill in:

• Country of establishment — the country where you are OSS-registered. Sales to this country remain handled by your usual WooCommerce configuration (outside OSS scope).
• VAT number — your intra-EU number (e.g. FRXX999999999). It appears in the return XML header.
• Company name, email, phone, IBAN, BIC — information used in the XML Operator block.

2. VIES validation

• Enable VIES validation — queries the European Commission service whenever a VAT number is entered at checkout (8-second timeout).
• Apply B2B reverse charge — sets VAT to 0% for intra-EU business customers whose number has been validated.
• VIES cache duration — in seconds, 30 days by default (2592000). Each validated number is cached to avoid hitting VIES unnecessarily.

3. Default activity type

Choose Goods or Services. This type is used to split revenue in thresholds and in the OSS return. You can override it per product: in each WooCommerce product, Tax tab, OSS type field.

EU VAT rates

The VAT OSS → VAT Rates page lists the 27 Member States with three columns: standard, reduced and super-reduced rate. Default values are up to date at plugin publication.

The rate applied at checkout depends on the product WooCommerce tax class: the standard class uses the standard rate, a class containing “reduced” uses the reduced rate, a class containing “super” uses the super-reduced rate.

Checkout behaviour

1. The customer fills in their billing country; the plugin automatically applies the country rate if the sale is intra-EU and OSS-eligible.
2. An optional EU VAT number field appears in the billing fields.
3. On input (600 ms debounce), an AJAX validation queries VIES and shows the result: green check with the company name, or red cross.
4. If the number is valid and reverse charge is enabled, VAT drops to 0% with the label “VAT (reverse charge)” and totals recalculate.
5. The number, validation status and company name are stored in the order metadata.

OSS sales tracking

Every order reaching Completed or Processing status is recorded in the tracking table, split by VAT rate and product type. Shipping costs attach to the dominant rate of the order. Refunds automatically generate negative lines.

Excluded from the OSS return: domestic sales (country of establishment) and B2B sales with a validated VIES number (reverse charge).

Dashboard

The VAT OSS → Dashboard page shows, for the current quarter: OSS net base, VAT due, comparison with the previous quarter, number of countries involved, detailed breakdown by country and rate, and the progress of each configured threshold.

Generating the OSS return

In VAT OSS → OSS Return, pick the year and quarter (the previous quarter is preselected), then click the desired format:

• Summary CSV — aggregated by country and rate, UTF-8 with BOM and semicolon separator. This is the file to use for manual portal entry.
• Detailed CSV — one line per order and rate, with order number, customer type and VAT number. Serves as accounting audit trail.
• FR-format XML — compliant with the DGFiP OSS-Union schema (namespace urn:dgfip:oss:union:v1), with Header, Operator, per-country Supplies and Totals blocks. Ready to upload to impots.gouv.fr.
• Everything as ZIP — all three files in one archive.

Configurable thresholds

The VAT OSS → Thresholds page lets you define as many thresholds as needed. Each row includes:

• Label — free text (e.g. “Sale of goods”)
• Amount and currency — the yearly ceiling to monitor
• Type — Goods, Services, or All (global revenue)
• Alerts (%) — comma-separated tiers (e.g. 80,90,100)

On every order, the plugin recalculates the yearly revenue of the relevant type. When a tier is crossed, an email is sent to the site admin address and a persistent notice appears in admin. Each tier only triggers one alert per fiscal year.

Three example thresholds (French micro-business regime) are pre-filled at install: 85,000 € goods, 37,500 € services, 25,000 € VAT exemption. Adapt them to your situation or remove them.

Maintenance

• Purge VIES cache — button in VAT OSS → Settings, forces revalidation of all numbers at the next checkout.
• Deactivation — keeps all data (table, options, history).
• Uninstall — removes the wp_vat_oss_sales table, all options, the VIES cache and order metadata (including the HPOS wc_orders_meta table).

Troubleshooting

VIES validation does not trigger

• Check that the PHP SOAP extension is installed on the server.
• Check that validation is enabled in VAT OSS → Settings.
• VIES undergoes regular maintenance on the European Commission side — try again later; the fallback with VAT applied protects your orders.

The applied rate is not the expected one

• Sales to your country of establishment use your native WooCommerce configuration, not the plugin registry.
• Check the product tax class: it determines whether the standard, reduced or super-reduced rate is used.
• Check the target country rate in VAT OSS → VAT Rates.

An order does not appear in the return

• Only orders in Completed or Processing status are recorded.
• B2B sales with a validated VIES number are deliberately excluded (reverse charge, outside OSS).
• Domestic sales are outside the OSS scope.

FAQ

Can I use the plugin outside France?

Yes. The country of establishment is configurable, thresholds are fully customizable and the interface exists in 5 languages. Only the XML export follows the French DGFiP schema; for other national portals, use the summary CSV.

Does the plugin handle the IOSS regime (imports)?

No, this version covers the OSS-Union regime (intra-EU sales). The IOSS regime for imports under 150 € is not included.

Is the data GDPR-friendly?

The plugin only stores data required for the tax return: country, amounts, rates and VAT number (business data). No data is sent to third parties apart from the official European Commission VIES call.