From Completed Work to Paid Invoice: A Workflow for Freelancers

An invoice can be mathematically correct and still sit unpaid because it reached the wrong inbox, lacks a purchase order number, or includes work nobody approved. Before changing the design of your invoice, check how it moves from your project records to the client's payment process.

The workflow below is for independent client work. The two sections marked Germany address German rules; they are not a tax checklist for every country.

Agree the billing process before starting work

Keep the commercial agreement with your project records. It should answer four practical questions:

• What is included? Name the deliverables, included revisions, chargeable meetings and expenses. Record how you will agree on additional work.
• What is the price? State the hourly rate or fixed price, currency, and whether quoted prices include applicable tax. Choose a payment method both sides can use and account for any processing costs in your pricing.
• When will you invoice? Agree on milestones, monthly billing or another trigger, along with payment terms. Distinguish delivery from any agreed acceptance or approval step.
• Where does the invoice go? Obtain the correct billing entity, address, invoice inbox or portal, required purchase order (PO) number, and the person who approves the work.

A project manager and an accounts-payable team may need different information. Ask who resolves a missing approval and whether a PO must exist before you begin. Save those answers rather than rediscovering them on every invoice.

For pricing preparation, the hourly-rate calculator and project-price calculator can help you explore your assumptions. Their estimates do not replace an agreed scope or determine the tax treatment of your invoice.

Turn work records into recognisable line items

Record work while the details are available: date, project, task, duration and whether it falls within the agreed scope. Separate internal administration from billable activity. Before doing an extra revision or expanding a deliverable, confirm the additional price or charging basis with the client.

An hourly service line could read:

Website redesign, mobile navigation implementation and testing, 1–3 October 2026, order PO-1042: 6 hours × €90 = €540 net.

This connects the charge to a deliverable, period and order. Apply the appropriate tax treatment separately; the example is not a complete invoice. For a fixed-price project, describe the agreed milestone and fixed amount instead of presenting your internal hours as the charging basis. Attach a timesheet if agreed, without exposing unrelated clients or private notes. Our freelance timesheet template and worked example includes a free fillable PDF and checks for durations and rounding.

Check the document before sending it

Compare the draft with the agreement and records. Have you used the correct legal customer, approved rate, service period and references? Do quantities, discounts and totals reconcile? Have earlier payments been accounted for where relevant? Show the payment instructions and agreed due date clearly. Keep a correction process that preserves what was originally sent rather than silently replacing that file.

Germany: invoice details are a separate check

For an ordinary VAT invoice, the main checks under § 14(4) UStG include both parties' full names and addresses, the supplier's tax number or VAT ID, issue date, uniquely assigned sequential invoice number, service description and date, net amounts by tax treatment, and tax rate and amount or an exemption reference. Agreed price reductions also matter. Special cases and simplified invoices require their own assessment; this is not an exhaustive checklist for every transaction. § 14 UStG.

Send it through the agreed route and record the result

Use the requested inbox or portal and the legally required format. A normal PDF is not a structured e-invoice under Germany's current rules, and domestic B2B requirements are being introduced with transitional provisions. Federal guidance on B2B e-invoicing.

For the German deadlines, exceptions and format choices, see our guide to e-invoicing for freelancers. Confirm the recipient's requirements before export, especially for public-sector customers.

Keep the sent invoice, supporting documents, submission date and any portal confirmation together. Record a rejection as something to resolve, not as a completed submission. If the client says it never arrived, you should be able to identify the file, destination and date without reconstructing your sent-mail history.

Follow up with a specific request

Maintain a list of invoice number, customer, amount, due date, payment status and next action. Check incoming payments before sending reminders. If the amount remains outstanding, contact the billing person, include the invoice again and ask for a payment date or the information still needed.

A short starting point, after checking the details:

Subject: Outstanding invoice [number]

Hello [name],

Invoice [number] for [amount], due on [date], is still outstanding according to my records. Please arrange payment and let me know when I can expect it. If anything is missing for approval, please tell me what is needed. I have attached the invoice again.

If you have already paid, please send the payment date and reference so I can match it. Thank you, [name]

If the reply promises payment, record the date and check again then. If it identifies disputed work or a missing approval, resolve that specific issue. Sending progressively firmer versions of the same message will not fix an incorrect recipient or an unexplained charge.

Germany: distinguish a reminder from default charges

When German law applies, a due debt and legal default (Verzug) are different. A payment demand after the due date can trigger default even if labelled a friendly reminder. A reminder may be unnecessary if a calendar payment date was agreed. The 30-day rule generally requires both a due debt and invoice receipt; consumers need a specific notice. Default is excluded while nonpayment is due to circumstances the debtor is not responsible for. § 286 BGB.

For payment claims in transactions with no consumer involved, statutory default interest is nine percentage points above the base rate per year. This is not a flat percentage penalty added whenever an invoice is late. Check whether default has begun and the base rate applicable to the period before calculating a claim. § 288 BGB. For disputed claims or escalation, get advice on the individual case rather than adding an arbitrary fee or assuming you can stop work.

Close the loop when payment arrives

Match the payment to the invoice and record the date, amount and any remaining balance. Keep a partial payment visible as partial. Retain the invoice and related records through your bookkeeping process, then note what caused any delay: missing PO, unclear scope, wrong destination or a payment dispute. Adjust the relevant step before the next project.

TimeBill brings time records, projects and invoice preparation together on your Mac. Whichever tool you use, give each outstanding invoice a next action and keep the agreement, work record and payment connected.