Agency Invoice Generator

Formula and inputs

The invoice total is retainer plus project fees plus pass-through costs plus approved extras, with tax where applicable. Pass-throughs should appear at documented cost, with any handling fee shown as its own transparent line rather than buried in a marked-up number.

Example scenario

Monthly retainer with media pass-through

An agency bills a client $11,300: a $6,500 management retainer, $4,200 in ad spend paid on the client's behalf with the platform statement attached, and a $600 landing-page revision approved by email on the 12th, referenced on the line.

• -Line item: Monthly retainer, $6,500
• -Line item: Ad spend pass-through (statement attached), $4,200
• -Line item: Approved out-of-scope revision (ref. 06/12 approval), $600
• -Payment terms: Net 15

Finance can match every line to a document: contract, platform statement, approval email. That is what gets an invoice paid in one pass. The pass-through at cost with attached evidence also defuses the most common agency billing dispute before it forms.

Common mistakes

• -Marking up pass-through media invisibly instead of showing a transparent handling fee.
• -Billing out-of-scope work without referencing when and how it was approved.
• -Letting retainer invoices drift in timing, which trains clients to treat due dates as soft.

How to interpret the output

• -If invoices stall in client finance, add documentation references per line before changing anything else.
• -Recurring 'small extras' on invoices signal scope creep; convert them into a bigger retainer or a rate card rather than monthly friction.
• -Watch days-to-payment by client; agencies fund slow payers with their own payroll, and that cost belongs in pricing.

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