Freelancers do not get paid when the work is done. They get paid when an invoice is approved, processed and transferred — and each of those steps can stall for reasons that have nothing to do with the quality of the work. Invoicing well is the part of freelancing that turns effort into cash on a predictable schedule.
This guide is about the routine around the document: what to agree before you start, when to send, how to structure payments for different kinds of engagement, and what to do when the money is late. For the anatomy of the invoice itself, see how to make an invoice and what to include on an invoice. The examples use Simple Invoice, a free, browser-only invoice generator, but the habits apply to any tool.
Agree the terms before the work, not on the invoice
The invoice is not the place to introduce your payment terms. By the time it arrives, the client has already budgeted the project and set their own expectations about when they will pay. Put the terms in the proposal or contract and repeat them on the invoice so there is nothing to negotiate at the end.
The minimum to agree in writing: the price or rate, what counts as billable, when you will invoice, how long the client has to pay, who covers transfer fees, and what happens if payment is late. If the client has a supplier onboarding process — a vendor form, a purchase order, a portal — complete it before the first invoice is due, because these processes can take weeks.
- Ask how the client pays: bank transfer, card, a payment service. Set up whatever they need in advance.
- Ask what the invoice must show: a PO number, a cost centre, a contact name, their tax id.
- Ask when they run payment. Many companies pay on fixed days; an invoice that misses a run waits for the next one.
When to invoice: deposits, milestones, retainers and completion
The right billing rhythm depends on the engagement. Choosing it deliberately is the single biggest lever a freelancer has over cash flow.
- Deposit. A percentage or fixed amount before work starts. It filters out clients who will not pay and funds the first weeks. On the final invoice, record it as amount paid so the balance due is what remains.
- Milestones. For projects longer than a few weeks, invoice at defined deliverables — discovery, first draft, final files. Each invoice is small enough to approve quickly, and a payment problem surfaces early instead of at the end.
- Retainer. For ongoing work, invoice a fixed amount on the same day each month, in advance. Use last month's exported copy as a reference, change the period and send.
- Hourly or daily. Invoice on a fixed cycle — weekly, fortnightly or monthly — with one line per day or task and the hours as quantity. Attach or reference the timesheet.
- On completion. Fine for short jobs and small amounts. For anything else, combine it with a deposit.
Set up once so each invoice takes minutes
Most of an invoice is the same as the last one. A good setup means a new invoice is only the lines that changed.
In Simple Invoice that setup lives on the document and in the sidebar: type From, Bill To and the invoice number on the page, then use the Layers, Template, Format and Labels sections. The template gallery shows the available starting points.
Because the app keeps one document in your browser with no account, use Export → JSON before replacing an invoice you would not want to retype.
Describe the work the way the client bought it
Approvers compare invoices to what they agreed. If the proposal said "three concept directions, two rounds of revisions, final files", invoice those three lines rather than "design services". If you bill hourly, one line per task or day with the hours as quantity; put dates and context in the details line under each description.
Keep extras separate and pre-approved. An unexpected line for "additional revisions" is the fastest way to turn an invoice into a conversation. Agree scope changes in writing when they happen, then invoice them as their own line referencing that agreement.
Numbering and records that survive an audit
Use a single continuous sequence for all clients. A prefix and a padded counter — INV-0001, INV-0002 — is enough; add the year if you file by year. Never reuse a number, never edit one after sending, and mark cancelled invoices void rather than deleting them so the sequence has no unexplained gaps. Invoice numbering best practices explains the options.
Keep every issued invoice as a PDF in a folder per tax year, alongside the JSON export of the app data. Tax authorities typically require invoices to be retained for several years; the exact period differs by country. A PDF and a backup file cost nothing to keep.
Taxes: know your status, then let the tool do the arithmetic
Whether you add VAT, GST or sales tax to your invoices depends on where you and the client are and whether you are registered. Registration is often optional below a turnover threshold and mandatory above it, and business-to-business sales across borders frequently follow special rules. None of this is a tool question — ask an accountant once and write the answer down. Our tax basics guide explains the terms you will hear.
Once you know your status, the invoice is mechanical: add the tax with its label and rate as a default, mark which lines are taxable, and the totals block shows the tax separately. If you are not registered, leave taxes off and, where local rules expect it, add a note saying tax is not charged.
Sending: make the invoice easy to file
Send the PDF as an attachment to the address the client gave for invoices — often a shared accounts mailbox, not the person you worked with. Use a subject line that contains the invoice number, the project and the due date. In the body, restate the amount, the due date and the payment reference, and say the invoice is attached.
Name the file so it sorts: Simple Invoice defaults the PDF name to the invoice number, Invoice INV-0042.pdf. If the client uses the app too, a share link opens a read-only copy in their browser without any file at all; the invoice travels inside the link and nothing is uploaded.
Tracking and following up
Simple Invoice deliberately does not track sent, paid or overdue statuses. Record the invoice number, due date and payment in your spreadsheet or accounting tool, and set a weekly reminder to review that list.
Follow up on the first business day after the due date, politely and with the facts: invoice number, amount, due date, attached again. Late payments are often administrative — the invoice was not forwarded, the PO did not match, someone was on holiday — and a factual reminder resolves them. Escalate on a schedule if it does not. These reminder templates give you the wording for each stage.
Getting paid faster
Small changes in how you invoice add up to a shorter gap between finishing the work and seeing the money.
- Shorter terms for smaller clients. Fourteen days is reasonable for individuals and small companies; large ones will insist on their standard term regardless.
- Invoice immediately. Sending on the day of completion rather than at month end can save weeks.
- Offer the payment method the client finds easiest, even if it costs a small fee.
- Put the balance due and the payment reference in the email body, not only in the PDF.
- Ask for the PO before you start, and put it on the invoice.
- Send the invoice to the accounts mailbox and copy your contact, so both the approver and the payer have it.
International clients
Cross-border invoices add three questions: which currency, which bank identifiers and which tax treatment. Agree the currency in the proposal and format the invoice for the client's conventions — Simple Invoice formats amounts and dates per locale and lets you rename every label, so a German client can receive 1.234,56 € and 12. September 2026 without you retyping anything. Provide IBAN and BIC for international transfers and say who pays the fees. How to invoice international clients goes into detail.
The freelancer's invoicing routine
Put the habits above on a schedule and invoicing becomes a fifteen-minute task rather than a source of anxiety.
- Before each project: terms in the contract, client onboarding done, PO in hand.
- On each billing date: prepare the document, adjust its number and lines, export the PDF and send it.
- Weekly: check your own records for overdue invoices and send reminders.
- Monthly: file the month's PDFs and any JSON copies you want to retain.
- Yearly: roll the numbering counter if you use a year token, review your default terms and rates.
Questions
Should I invoice before or after the work?
For anything longer than a short job, both: a deposit before you start and the balance on completion, or milestone invoices along the way. Retainers are invoiced in advance. Invoicing only on completion puts all the risk on you.
Can I charge a late fee?
Often yes, if it was agreed in advance and is permitted where you operate; many jurisdictions also set a statutory right to interest on late commercial payments. State the policy in your terms before the work. Invoice payment terms explained covers the wording.
Do I need paid invoicing software as a freelancer?
Not for producing the document itself. A free local-first tool covers templates, numbering, taxes and PDF export. Paid tools add servers — status tracking, emailed invoices, online card payment, sync and accounting integrations. Simple Invoice vs FreshBooks lays out when each is worth it.
What if I am not registered for VAT or sales tax?
Then you generally do not charge it or show a tax line. Some countries expect a note on the invoice stating that tax is not charged and why. Ask your accountant which wording applies to you.