Convert invoices by email: how the channel works
Official references
Use these sources to verify dates, formats, and official rule changes.
Related Technical Wiki
Explore deep-dive developer documentation and regulatory guidelines matching this article.
Common integration error codes explained for non-technical users.
What to check before turning ERP, PDF, or spreadsheet invoice facts into structured XML.
Why human review is part of reliable invoice conversion.
Article overview
This article explains Convert invoices by email: how the channel works as a practical reference for European e-invoicing. It defines the topic in plain language, places it in the compliance context, and connects the explanation to invoice formats such as XRechnung, ZUGFeRD/Factur-X, UBL, and CII.
The email channel converts genuine PDF invoice attachments and returns validated artifacts in the same thread. It is an account-enabled Enterprise channel for controlled, low-volume workflows.
How to use this guide
Use the article as a starting point before changing a finance or ERP workflow: identify the applicable country rule or standard, decide which structured format is expected, validate the generated XML, and keep a documented exception process for invoices that require manual review.
Setup and first conversion
For Setup and first conversion, this sequence gives the practical order of work.
- Ask the Invoice Converter team to enable the email channel.
- In the account profile, add and verify every sender address. Choose the reply destination and language.
- Copy an inbox from the profile. The generic inbox needs exactly one subject tag such as [XRechnung], [ZUGFeRD], [EN16931], [UBL], or [CII].
- Attach genuine PDFs and send the message. Each accepted PDF uses one conversion unit.
- Open the threaded reply and review the issued file plus its HTML validation report.
Important limits
Only verified senders are processed. The channel accepts genuine PDF attachments, not renamed images. Low-confidence cases and warnings still need human review. Available units must cover the full message before processing begins.
Email or API?
Use email when a person or mailbox rule benefits from a reply thread. Use the External API when a system needs idempotency, task status, rate-limit information, and explicit downloads.
See the current email channel
Review setup, subject tags, outputs, billing, limits, and human-review rules.
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