# Set a custom filename for outbound EDI files

> You can now set custom filenames for generated EDI files from within outbound transaction settings.

Published May 15, 2024

Product: EDI platform

You can now set custom filenames for generated EDI files within outbound transaction settings.

By default, Stedi autogenerates a unique name for outbound files using a UUID. To specify a custom filename, open **Advanced settings** in the outbound transaction setting and enter a JSONata expression into the **Filename expression** field.

You can use `& (Concatenation)` or `$millis` in the expression to generate a unique name based on the processing timestamp. For example, the expression `“EDI850-” & $millis()` results in filenames like `EDI850-5182341242`.