How to rename a charge or metric label on a Lago invoice

You can rename the label a charge or billable metric shows on an invoice, for example replacing "Units" with "API calls" or "Function calls," using the charge's invoice display name. This is set per plan or subscription and changes only how the charge is labeled. The "Units" column header in the line item table is a separate thing: it belongs to the fixed PDF template and cannot be renamed from settings.

How to set the invoice display name

Open the plan or subscription, find the relevant charge, click the pencil icon next to the charge name, then set the Invoice display name. The new label appears on every invoice generated from that plan going forward. It does not change the underlying billable metric name and does not affect any reporting.

Renaming the "Units" column header

The column header "Units" in the quantity/price/amount table is part of the PDF template, not a charge label, so the invoice display name does not touch it. Renaming it means modifying the template itself, which on self-hosted deployments requires editing the invoice HTML directly and is not recommended. See the separate article on what cannot be changed without editing the template.

This article reflects guidance drawn from customer case resolutions. It is not officially supported documentation and may not apply to all situations.