Invoices & Billing

What it is: Invoices from billable time or fixed fees, with tax, due dates and aging.

Overview

Works out the smallest useful Invoices & Billing setup for the business in front of it, then builds it only when asked. The default output is a short recommendation, not a spreadsheet. Artifacts - CSV, SQL DDL, JSON Schema, Notion mapping - are produced on request, from one field list so they cannot drift apart.

Layer: Layer 8: Operate. Fits: Starter stage. Table code: n/a.

When to Use This Skill

• invoice tracker
• billing spreadsheet
• invoice register
• accounts receivable aging

Also use it when the user says "invoices from billable time or fixed fees, with tax, due dates and aging", or describes the same process happening in a spreadsheet, a document or someone inboxes.

Do not use it for: payroll calculation, tax filing, or legal advice. This skill produces empty templates only - it never holds or processes real employee or customer data.

How It Works

Follow the shared execution contract. The module-specific rules below define only domain fields, decisions, calculations, and safety constraints.

Step 1 - Identify intent

Read the request and pick the intent before asking anything.

• "set up" or "build" or "create" -> the user wants artifacts; go to Step 2.
• "our process is ..." or "it is in a sheet" -> the user wants to move an existing process; capture it, then Step 2.
• "is this right" or "review" or "audit" -> the user wants a check, not a build; answer from what they share.
• "how do I ..." -> advice question; answer directly and offer the build only if it helps.

Ask only if this is the highest-value missing fact; otherwise proceed without an opener:

Q: How do you bill clients today?

Step 2 - Ask only what is missing

Skip anything the user already answered, in any earlier message. Ask the rest one at a time, and stop as soon as the remaining answers would not change the output.

• Billing - How many clients? / Monthly, milestone or hourly? / Invoices raised by whom?
• Terms - Payment terms? / Retainer or one-off? / Any late fees?
• Tracking - How is status tracked? / Sent, due or overdue? / Who chases?
• Current process - What tool today? / Accounting package or sheet? / What gets missed?
• Outcome - What do you need? / An invoice record, a template or both?

Never invent an answer. If the user does not know, record it as unknown and carry on.

Step 3 - Hold the internal context

Hold the answers in this shape. It stays internal - it is not shown to the user unless they ask, and it never carries a value the user did not give.

module: invoices-billing
intent: null            # setup | advice | review | fix | build | convert | export
scale: null             # Starter | Growth | Scale, only if the answer changes it
areas:
  "Billing": null
  "Terms": null
  "Tracking": null
  "Current process": null
  "Outcome": null
requested_outputs: []   # csv | sql | json | notion | xlsx - requested formats only
confirmed_facts: []     # only what the user actually said
open_questions: []      # the unanswered ones, in the order worth asking

Step 4 - Recommend the smallest workflow

If an artifact was requested, build it after resolving essential missing facts. Otherwise give a short recommendation and offer the relevant artifact.

Recommended approach: One invoice record with the client, the amount, the due date and the status, and let the accounting package handle the actual invoice document.

Why this one: Billing problems are chasing problems. A due date and a status per invoice is the minimum that makes chasing possible.

Workflow: Work recorded → Invoice raised → Status tracked → Chased → Paid or overdue

Step 5 - Build only on request

Once the user asks for it, derive the fields from the confirmed context and emit the requested artifacts. For machine-readable text, keep prose outside the data; for files, provide a usable link. Report material validation failures or limitations separately.

A selected Notion output is rendered by notion-manual-import, so route the Notion step there. When the user selects Notion, hand that step to @notion-manual-import: it holds the CSV, the property mapping, the import steps and the verification checklist, and it renders the Field Reference below instead of defining a table of its own. Do not restate the mapping

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