Labels are the words printed on the document itself: Invoice number, Due date, Name/description, Quantity, and the rest. Changing them to the wording your industry or your customers expect is simple.
Change labels in the document design
- Go to Settings → Document designs, pick the language and open the design.
- Stay in Document design mode and scroll the left column to Field names and values.
- Switch Use default design off — until you do, this design just follows the base one and there is nothing to edit.
- Click Modify Field names and values.
- In the pop-up, type your wording into the Field name column beside the field you want to rename. Leaving it empty keeps the standard label — the grey text you see is the current one.
- Click Modify Field names and values to close the pop-up, then Save the design.
Every document created with that design uses your wording from then on.
Default values, in the same place
The same table has Show default value and Field default value. Together they let a field print a fixed value when the document does not carry one of its own — useful for something that is always the same on your documents and never worth typing.
Labels and language
Labels belong to the document design, and designs are held per language, so edit them in the design for the language you send that document in. Renaming Due date on your English invoice leaves the Dutch one untouched.
Labels vs the document title
The title printed at the top of the document is not a label — it is set on the design itself, in General → Document Name, and shown in the Title column of the designs list. See Document title vs document name.