Suggestions appear as you type. Use the up and down arrows to choose one and Enter to open it.

This page's audience real numbers from our own analytics — open to see them
–Visitors
–Page views
–Clicks to vendors
–Time on page
–Reading now
Clicks to vendors, by tool
  • –
Top countries
  • –
Devices
  • –

– · counted by iTechGuides's own first-party analytics, bots removed, every figure rounded down · how we count

phase4

Free#30 of 32 in Electronic Invoicing Software

phase4: A self-hosted Java library for teams building Peppol document exchange systems. Ranked #30 of 32 in Electronic Invoicing Software by our editors (5.8/10); pricing: Open source; best for self-hosted Peppol infrastructure teams.

5.8/10Editor score
Visit phase4
phase45.8 Visit phase4

At a glance

  • Editor score
    5.8 / 10
  • Pricing
    Open source
  • Best for
    Self-hosted Peppol infrastructure teams
  • Free plan
    No
  • Paid from
    None
  • Peppol access
    Yes
  • Founded
    2015
  • Facts checked
    20 Sep 2026
phase4 screenshot

  • Where it wins

    • Supports AS4, Peppol eDelivery, CEF eDelivery and SBDH
    • Includes SMP lookup and endpoint discovery for Peppol
    • Provides Java client, server, servlet and HTTP endpoint components

  • Where it doesn't

    • Not a hosted invoicing application for end users
    • Standalone functionality does not include business-document validation
    • Requires developer resources to embed and operate on-premise

Our verdict on phase4

phase4 is an open-source, embeddable Java library for sending and receiving AS4 messages in existing systems. It is intended for developers building e-invoicing, e-procurement and other business-document exchange solutions, rather than businesses looking for a hosted application. The project provides client and server components, supports UBL structured documents, and can be deployed on-premise through self-hosted and API-oriented use cases.

Its strongest fit is Peppol and eDelivery infrastructure. phase4 supports the Peppol eDelivery network, CEF eDelivery and several related ecosystems, including BDEW, DBNAlliance, eDelivery2, ENTSOG, EUCTP and HR eDelivery. Peppol-specific capabilities include SMP lookup and endpoint discovery, while SBDH construction and handling support document exchange workflows. HTTP endpoints, servlet-based inbound message processing and Peppol reporting support give implementation teams building blocks for integrating message exchange into existing systems.

The main trade-off is scope. phase4 supplies transport and infrastructure components, not a complete invoicing product with a hosted user interface or standalone tax validation. Its example server functionality and library components are suited to teams that can manage on-premise deployment and application integration. Business-document validation is handled through related phive and phive-rules projects rather than included in the standalone example. Choose phase4 when your team needs open-source Java infrastructure for Peppol or AS4 exchange; choose another product when you need an end-user invoicing application or built-in tax validation.

phase4 pricing

Plans Open sourceFree Free to use — no paid tier required for the core job.
See plans on github.com

phase4 fact sheet

Free planNo
Paid fromNone
Peppol accessYes
Tax validationNo
API accessYes
Invoice limitNot verified
Structured formatsUBL
DeploymentOn-premise
DeploymentSelf-hosted
SupportCommunity, Docs
Built forSmall business, Mid-market, Enterprise (editorial estimate)
Integrations8 integrations: Peppol, CEF eDelivery, BDEW, DBNAlliance, eDelivery2, ENTSOG …
PricingOpen source
Websitegithub.com
Facts checked20 Sep 2026

phase4 integrations

phase4 lists 8 integrations on its own site.

  • Peppol
  • CEF eDelivery
  • BDEW
  • DBNAlliance
  • eDelivery2
  • ENTSOG
  • EUCTP
  • HR eDelivery

Alternatives to phase4

See all phase4 alternatives →

Used phase4? Be the first to review it

The editor score above is our own research. What this page doesn't have yet is a reader's view — what you used phase4 for, what worked and what didn't. No stars are seeded and no review is paid for; an editor reads every one before it appears.

Write a reviewTwo minutes · verified accounts only · read by an editor before it appears

Reviews come only from verified accounts. Sign in or create an account first — your e-mail is never shown.

Your rating

0 characters · at least 80, up to 3,000

Posted from your verified account. Reviews appear after an editor reads them, usually within two working days.

Featured on iTechGuides

Featured on iTechGuides — phase4 5.8/10

phase4 is listed in our Electronic Invoicing Software directory. Add the badge to your site — it links back to this page.

<a href="https://www.itechguides.com/products/phase4/"><img src="https://www.itechguides.com/best/badge/phase4.svg" alt="Featured on iTechGuides" width="230" height="46"></a>

Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026

Advertiser disclosure: iTechGuides is reader-supported. We may earn a commission when you click some links. How we rank.

Last updated · How we research and update