How to Bill a Client: Complete Guide for Freelancers and Consultants
Billing seems simple until you're chasing a β¬5,000 invoice for the third month. Here's how to do it right from the start.
In this guide
Before the project starts
Most billing problems are caused by things that weren't agreed before work began. Fix these upfront and you'll rarely need to chase.
- βAgree on billing structure upfront β put it in a proposal or email. Hourly? Fixed fee? Milestone? Retainer? Be explicit.
- βGet it in writing β even a reply-confirmation email is legally binding in most jurisdictions. A signed contract is better, but written confirmation is enough.
- βDiscuss payment terms β how many days do they have? Net 14, 30, 45? Larger companies often have 30 or 45-day AP cycles. Know this before you start.
- βGet the billing contact β get the name and email of the person who actually processes invoices. Your project contact may not be the one approving payment.
- βAgree on invoice format β some companies require a PO number on every invoice, or a specific format. Missing a PO number can cause weeks of delay.
How to structure your billing
The billing structure you choose affects your cash flow, your risk, and how easy the project is to manage. Here are the five main models.
β± Hourly billing
Track time carefully and show hours Γ rate on the invoice. Best for open-ended projects where scope isn't fully defined. Risk: clients can dispute hours if you don't keep detailed records.
π Fixed fee
Tied to deliverables, not hours. Protects you if you work fast β and exposes you if scope creeps. Always define what's included explicitly. Add a change request clause.
π Milestone billing
30/30/40% or similar splits tied to project phases. Reduces cash flow risk on long projects. Each milestone invoice is triggered by a clear, agreed deliverable.
π Retainer
Monthly flat fee for ongoing work. Easiest to invoice and forecast. Define what's included in the monthly scope β and what triggers an additional invoice.
π Value-based pricing
Charge based on the value you deliver, not the hours you spend. Highest ceiling of all models. Requires a clear ROI case and a client who understands the value.
Creating and sending the invoice
The mechanics of sending an invoice matter more than most freelancers realise. Sloppy invoicing signals a sloppy business.
When to send
Send immediately on completion β not "later this week." Every day you delay invoicing is a day added to when you get paid. Same-day invoicing is professional, expected, and appreciated.
What to include
Full line item details (don't just write "consulting"), a unique invoice number, the due date, and at least one payment method. If you accept bank transfer and card, list both.
How to send
Email with a PDF attachment, plus a payment link directly in the email body. Don't make clients download and open an attachment to find out how to pay. Remove friction.
Subject line and recipients
Use: Invoice #[N] for [Project] β due [date]. CC the billing contact AND your primary project contact if they're different people. Both need to know the invoice exists.
Following up on unpaid invoices
An invoice that isn't chased is an invoice that won't get paid. Most late payments aren't malicious β clients are busy, invoices fall through the cracks. Your job is to keep it visible.
Friendly reminder
"Just following up on invoice #001 β wanted to make sure it landed in the right inbox."
Firmer follow-up
"Invoice #001 is now 14 days overdue. Please confirm when payment will be processed."
Formal notice
Reference your late fee policy. Request immediate payment or a payment plan in writing.
Final notice
Warn of escalation: collections, small claims court, or professional debt recovery. Keep all records.
Keep records of every follow-up email β timestamps, content, and any client responses. This documentation is essential if you escalate to collections or legal action.
Automating client billing with Chaser
The reason most freelancers don't follow up on invoices isn't laziness β it's the emotional energy. Sending a third reminder to a client you have a good relationship with feels awkward. Chaser removes that friction entirely.
Add your invoice once. Chaser automatically sends all four follow-up stages β each escalating in tone β and includes a payment link in every email. You get notified when payment lands.
- β4-stage escalation sequence, sent automatically
- βEach email increases in urgency β friendly to formal
- βPayment link included in every reminder
- βDashboard shows every invoice and its current stage
- βFree for your first 3 invoices β no credit card needed
Stop chasing. Start automating.
Chaser sends escalating invoice reminders automatically. Add an invoice once β Chaser handles the rest. Free for 3 invoices.
Try Chaser free βNo credit card required
Frequently asked questions
When should I send an invoice to a client?
Send it immediately on completing work or hitting a milestone β not "later this week." The longer you wait to invoice, the longer you wait to get paid. Same-day invoicing is professional and sets expectations.
What are standard payment terms when billing clients?
Net 30 is the most common for B2B freelance work. For smaller projects or newer clients, Net 14 or even Net 7 are reasonable. Always agree on terms before starting and state them clearly on every invoice.
How many times should I follow up on an unpaid invoice?
Follow up at 7, 14, 21, and 30 days. If unpaid after 30 days, escalate to a formal demand letter or consider collections. Four follow-ups is the professional standard β persistent but not aggressive.
Can I charge late fees when billing clients?
Yes, if you've stated the late fee policy upfront (in your contract or on your invoices). Standard is 1.5% per month or a flat fee. Courts generally enforce these if agreed in advance.
What's the best way to avoid late payments from clients?
Take a deposit upfront (25β50% for new clients), use milestone billing for longer projects, send invoices immediately on completion, and use automated reminders so follow-up isn't dependent on your emotional energy.
Related articles
Invoice Payment Terms Explained
Net 7, Net 30, 2/10 Net 30 β what they mean and when to use them.
Overdue Invoice Email Templates
Copy-paste follow-up emails for every stage of a late invoice.
How to Ask a Client for Payment
Scripts for awkward payment conversations that actually work.
Invoice Follow-Up Email Templates
4-stage follow-up sequence from friendly reminder to final notice.