POP is an e-invoicing compliance plugin for WooCommerce, Paid Memberships Pro and Cozmos PMS. It focuses on structured XML and on the full e-invoicing lifecycle, including generation and validation, network submission and, if enabled, digital signature and compliant archiving.

With POP you pay a subscription and receive a monthly allocation of API credits. One credit equals 1 API call, for example: generate or validate XML, submit to a network (SdI, PEPPOL, KSeF and others), plus signature and archiving when enabled. The principle is simple: you know in advance what you spend, and monthly costs remain predictable.

POP supports country-specific e-invoicing workflows for Italy, San Marino and Belgium, including direct delivery to Italy’s Exchange System (SdI) and Belgian structured e-invoicing support.

POP can also be used for PEPPOL-based electronic invoicing workflows in the Netherlands, France, Germany and the United Kingdom.

Poland

POP supports invoice generation and related plugin features for Poland, including XML and PDF document generation, invoice numbering, fiscal configuration and other supported workflow features.

Transmission to the Polish national e-invoicing system is not currently available.

POP is also available for Shopify: https://apps.shopify.com/pop-european-invoicing
POP is available in five plans (Free, Basic, Growth, Pro and Enterprise). For paid features, visit: https://popapi.io/pricing/.

Below are the features included in the Free plan.

Document Generation & Delivery

Automatic generation of XML electronic invoices and PDFs for all completed orders
The Free plan includes 20 API credits/month. Credit consumption depends on the operation performed
Manual download of invoices in PDF or XML format
Compatible with selected European e-invoicing workflows, depending on the country, endpoint and selected plan

Tax Management

Supports invoicing data for EU and international customers, while structured e-invoicing workflows depend on the configured country and network
Configuration of tax regimes and VAT treatments
Regulatory references for exempt transactions

Verification and Data Control

Tax ID validation at checkout, where supported
Customizable invoicing fields: VAT number, tax ID and, depending on the country, destination code or PEPPOL ID

Document Numbering and Configuration

Fully customizable invoice numbering (prefix, suffix, yearly reset)
Progressive numbering for invoices, credit notes and receipts
Automatic blocking of invoices with a zero total
Exclusion of zero-value line items from invoices

Management and Reporting

Filters for invoices by date, type and WooCommerce order status
Search by invoice number or order ID
Full integration with WooCommerce e-invoicing
No limit on the number of WordPress installations and supported integrations

Network and supported formats

POP is designed to operate within structured European e-invoicing ecosystems, supporting both national interchange systems and the PEPPOL international network.
It enables compliant document generation and routing according to the technical and regulatory requirements of each jurisdiction.

Supported transmission networks

Italy – SdI (Sistema di Interscambio)
Direct transmission of structured XML invoices to the Italian Exchange System (SdI), where B2B and B2C e-invoicing is mandatory.
PEPPOL network (via certified Access Point)
Transmission of structured e-invoices through the PEPPOL international network, including:
Belgium (mandatory B2B e-invoicing for VAT-registered businesses from January 1st, 2026)
Netherlands
France
Germany
United Kingdom

In Belgium, structured B2B e-invoicing is implemented via PEPPOL. In other listed countries, PEPPOL delivery may be required contractually or for interoperability purposes, depending on the business context.
Regulatory obligations may vary by country and transaction type. Users remain responsible for verifying their specific compliance requirements.

Supported document formats

Structured XML e-invoices, including UBL where applicable
PDF invoice copies (human-readable representation)
Credit notes in XML and PDF format
Fiscal receipts, where supported by the configured workflow

POP supports B2B e-invoicing use cases. B2G use cases are not currently supported.

POP API and Integrations

Several advanced capabilities (such as automatic interchange system submission, qualified electronic signature and certified digital preservation) are now built directly into POP, depending on the selected plan, country and workflow.
Thanks to these built-in capabilities, POP works as a complete invoice generation plugin, automating XML creation, signing, transmission and long-term preservation through a fully structured, compliant e-invoicing workflow.

Invoice Options

With POP you can customize your invoicing workflow by configuring:

Invoice prefix and suffix
Automatic progressive numbering
Custom fields (Tax Code, Destination Code or PEPPOL ID and more)
Automatic sending of PDF invoices via email
HTML invoice display

Supported Payment Methods

Cash
Bank Transfer
Check
Payment Cards
SEPA Direct Debit

Compatibility

POP is compatible with the latest versions of WordPress and WooCommerce:
* WooCommerce: up to version 9.x.x; HPOS supported starting from WooCommerce 9.x.x
* PHP: 5.6 or higher
* WordPress: 4.6 or higher

For HPOS and optimal performance, we recommend using WordPress 6.x.x and WooCommerce 9.x.x and up.
We understand how frustrating it can be to navigate complex tax regulations, cumbersome tools, and the fear of making costly mistakes. We’ve been there too. It is precisely from these daily challenges that POP was born: a practical solution to real problems.
We didn’t want just another software. We wanted a simple, immediate, and truly useful solution. A way to automate tax management, reduce time wastage, and make room for the growth of your business, without the burden of bureaucracy.
POP is born from direct experience. It is designed to be clear, reliable, and perfectly integrated into your daily workflow.
We can’t make compliance sexy, only easier.

Contributions

“POP – European electronic invoicing for e-commerce (ex-WooPop)” is open source software.
Contribute to its development to continuously improve the plugin!

F.A.Q.

Is the POP plugin free?

Yes. POP offers a Free plan that includes 20 API credits per month.

A credit is the unit used to measure credit-consuming API operations. Some plugin features are included without credit consumption, while operations such as XML generation, transmission, electronic signature or archiving may consume credits depending on the configured workflow.

To unlock more credits and advanced compliance features, you can activate a paid plan.

Why does POP use API credits instead of “invoices per month”?

POP is an e-invoicing compliance product. A single invoice may involve multiple compliance actions, such as:

Generate and validate XML
Submit XML to a network (SdI, PEPPOL, KSeF, etc.)
Apply digital signature (if enabled)
Activate compliant archiving (if enabled)

Each action corresponds to 1 API call = 1 credit.

Can I automatically send invoices to tax authorities?

Starting from the Basic plan you can integrate POP with the supported networks such as SdI or PEPPOL, automating the sending of electronic invoices directly from your e-commerce.

POP also supports invoice generation and related plugin features for Poland, but transmission to the Polish national e-invoicing system is not currently available.

Is it possible to customize invoices generated with POP?

Yes. You can customize the PDF invoice template by adding your company logo and custom footer text. You can also configure invoice prefix, suffix and progressive numbering.

Does POP support invoicing for foreign customers?

Yes. POP supports EU and international customers and can route structured XML through supported networks. Regulatory requirements may vary by jurisdiction, and users should verify their specific obligations.

Is it possible to generate Credit Notes with POP?

Yes, starting from the Growth plan, you can generate and manage Credit Notes in XML or PDF format directly from the plugin.

What happens if I run out of credits?

This answer applies to the WordPress (Open Source) version of POP.

Free plan: the service stops when credits are exhausted.
Paid plans: overquota is allowed. Extra API calls are charged according to your plan’s overquota rate.

You can upgrade your plan at any time to increase your monthly credit allocation.

Please note that credit enforcement rules may differ on non open-source platforms.

Can I use POP only to generate XML without network submission?

Yes. POP can be used exclusively for XML generation and validation.

Network submission, digital signature and compliant archiving are optional modules depending on your workflow and selected plan.

Does the plugin offer customer support?

Yes. For support requests, you can contact us directly via the support link in the plugin or open a ticket from our official website.

Requirements

PHP: >= 5.6
WordPress: >= 4.6

POP – Free European electronic invoicing for e-commerce (ex-WooPop)