How to add manual fees to a draft invoice

Last updated: June 19, 2026

Lago lets you manually add line items to a draft invoice before it is finalized. This is useful for one-time charges, billing adjustments, or charging one customer for usage incurred by another. The feature requires a premium Lago license.

How it works

When an invoice is still in draft status, you can add a fee by selecting a charge and specifying either a total amount or a total unit count. Lago computes the line item total from the values you enter before the invoice is finalized.

The two adjustment types behave differently. Total amount takes a unit count and a unit price, then computes the total from those two values. Total units takes a unit count only and applies the existing unit price already defined on the charge.

Total units is not available for all charge models. It is disabled for percentage charges, dynamic charges, and graduated charges with proration enabled. For those models, only Total amount is available.

How to add a fee

  1. Open the draft invoice in the Lago UI.

  2. Click + Add a new fee at the bottom of the invoice.

  3. Select the charge (billable metric) you want to add.

  4. Optionally enter an invoice display name.

  5. Under Adjustment, choose Total amount or Total units and enter the relevant values.

  6. Click Adjust Fee.

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