Reference
Supported file formats per intake channel
Which formats FlowEngine accepts in the browser, in the mobile app and through email intake, which are processed automatically and which size limits apply.
Last reviewed October 30, 2026 · Version 2026.10
This reference shows which file formats FlowEngine accepts through which intake channel and which of them are processed automatically. Accepted means that FlowEngine stores the file. Processed means that FlowEngine recognizes text, document type, header data and line items in it.
How FlowEngine checks the file type#
FlowEngine determines a file's type on the server from its content. Neither the file name nor what the sending program declares decides. Files whose content does not match a supported format are rejected, for example HTML pages, SVG graphics, programs, archives or Office files with macros.
For uploads in the browser and with the mobile app, the file extension must also match the content. Closely related formats count as matching, such as a PNG image with the extension .jpg or an XLSX workbook with the extension .xls. FlowEngine identifies files without an extension by their content alone. Email intake does not check the extension, because email programs often send attachments without an extension or with a different one.
Format matrix#
| Format | Browser: file dialog | Browser: drag and drop | Mobile app | Email intake | Automatic processing |
|---|---|---|---|---|---|
| yes | yes | yes | yes | yes, with text layer and through text recognition (OCR) | |
| JPEG, PNG | yes | yes | yes | yes | yes, through text recognition |
| WebP | yes | yes | no | no | yes, through text recognition |
| TIFF | no | yes | no | yes | not guaranteed |
| HEIC, HEIF | no | yes | yes (import) | no | not guaranteed |
| Excel (XLSX, XLS) | yes | yes | no | no | yes |
| CSV | no | yes | no | no | yes, as a table |
| Word (DOCX, DOC) | yes | yes | no | no | no: the file is stored and shown as text, but not recognized |
| XML e-invoice (e.g. XRechnung) | no | yes | no | yes | only with active invoice management, which is not yet generally available |
| Text file (TXT) | no | yes | no | no (rejected) | no |
| Email forwarded as attachment (EML) | no | no | no | yes | FlowEngine reads the attachments it contains, up to three levels deep |
"Not guaranteed" means: FlowEngine accepts the file, but whether it can be processed depends on how your installation is set up. For reliable processing, convert such files to PDF, JPEG or PNG first.
When importing from other apps, the mobile app offers PDF, JPEG, PNG and HEIC; camera photos are uploaded as images.
Size limits#
| Channel | Limit | Notes |
|---|---|---|
| Browser | 20 MB per file in the upload area; on the server also your company's upload limit | The smaller value applies. |
| Mobile app | 20 MB per file in the app; on the server also your company's upload limit | The smaller value applies. |
| Email intake | your company's upload limit per attachment; at most 10 attachments per email, embedded images included; email text at most 16 KB | The mail gateway also limits the whole message, to 25 MB including encoding in the standard setup. Attachments grow by about a third when sent. For the email text, the plain-text and HTML versions count together. |
Your administrators set the company's upload limit under Settings → Security policies: 10, 20, 50 or 100 MB, 20 MB by default. A limit higher than 20 MB currently has no effect in the browser or in the mobile app, because both reject files over 20 MB themselves.
What happens when a file is rejected#
| Situation | Message |
|---|---|
| Extension not supported in the browser (drag and drop) | "“…” has an unsupported file format and was not added." |
| Content does not match a supported format | "this file type is not supported …" |
| Extension does not match the content | "the file extension does not match the file content …" |
| File too large | in the browser: "“…” is …; the limit is 20 MB." |
| Malware found | "uploaded file was rejected because malware was detected" |
If FlowEngine rejects one attachment of an email, the whole message appears in the Inbox with the status Error. The permitted attachments of that message are then not processed either. Send them in a new email without the rejected attachment.