# Convert invoices by email: how the channel works

- Date: 2026-07-29
- Reading time: 4 min read

Convert invoice PDFs by email: enable the Enterprise channel, verify senders, choose a format, send attachments, and review the reply.

## 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](/en/blog/invoice-conversion-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.

[Open the email guide](/en/developer-api/email-invoices)

## FAQ

### Can any sender use the address?

No. Each sender must be added and verified for the enabled Enterprise account.

### Does the service forward the invoice to my customer?

No. It returns results to the configured sender or collective address. You control the later delivery.

## Official references

- [Invoice Converter email channel](https://www.invoice-converter.com/en/developer-api/email-invoices)
- [OASIS UBL 2.1 specification](https://docs.oasis-open.org/ubl/os-UBL-2.1/UBL-2.1.html)