The short version: Send your invoice the moment the work is delivered, not when it suits you, because every day you wait is a day you’ve given the client an excuse to forget, deprioritise, or renegotiate what they owe you. For ongoing work, invoice on a fixed schedule (weekly, fortnightly, or monthly) rather than “whenever I get round to it.” For big projects, get a deposit before you start a single hour of work.
The invoice I sent six weeks late
In 2019 I ran a one-day workshop for a fintech company in London. Good day, good energy, the client seemed thrilled. I flew home, got straight into three other client deadlines, and told myself I’d invoice “next week.” Next week became five weeks. When I finally sent it, the person who’d booked me had left the company and the new marketing lead had no idea the workshop had even happened, let alone that £4,000 was owed for it. It took four months and three increasingly awkward emails to get paid, and I only got it because I still had the original signed proposal in my inbox as proof.
That’s the bit nobody tells you: the invoice isn’t paperwork you tidy up afterwards. It’s the thing that proves the work happened at all. Wait too long and you’re not just delaying payment, you’re giving the client’s memory, their budget cycle, and their staff turnover time to work against you.
The actual rule: invoice on delivery, not on convenience
The simplest, most reliable rule I use now and teach every client I coach through this: the invoice goes out the same day the deliverable lands, or within 24 hours at the absolute latest.
- Finished a logo design and sent the files? Invoice goes out that afternoon.
- Delivered a written report? Invoice attached to the same email as the final version.
- Ran a training session? Invoice sent before you’ve left the building, or that evening.
Why same day and not “within a week”? Because the moment the work lands is the moment the client feels the value most strongly. Wait a week and you’re invoicing someone who’s already moved on to the next thing. Wait a month and, as I found out, you’re invoicing a company that might have replaced the person who hired you.
Different work, different invoice timing
Not every freelance job has the same rhythm, so the timing rule needs to flex depending on what you’re doing.
Project-based work
For anything with a clear start and end point, use this three-invoice pattern:
- Invoice 1 (deposit): 30 to 50 percent of the total, sent before you do any billable work, due on receipt. If a client won’t pay a deposit, that tells you something about how the rest of the project will go.
- Invoice 2 (milestone): If the project runs longer than two or three weeks, invoice at a natural halfway point (draft delivered, first round of designs approved, etc), not at the very end.
- Invoice 3 (final): Sent the same day as final delivery, not when the client “signs off,” because sign-off can take weeks and you shouldn’t be unpaid while you wait for it.
Hourly or retainer work
Pick one day and stick to it religiously. I invoice every retainer client on the 1st of the month for the previous month’s work. Not the 28th, not “whenever I finish my time tracking,” the 1st. Clients who pay you monthly get used to a rhythm, and a predictable invoice date makes you look like someone running an actual business rather than someone scrambling for cash. If you’re building your invoicing habits from scratch, this guide on how to invoice correctly as a sole trader walks through the exact numbering and dating conventions that make a fixed schedule easy to maintain.
Retail, products, or one-off small jobs
Payment on delivery, full stop. There’s no reason to extend credit terms for a £200 job. Invoice and take payment (or send a payment link) before or at the point you hand over the work.
What “net 30” is costing you
Here’s the part most freelance advice glosses over: payment terms aren’t a formality, they’re a decision about how long you’re willing to work for free.
Net 30 means you finish the work today and don’t get paid until 30 days from the invoice date. If you invoiced late on top of that, say a week after delivery, you’ve turned a 30-day wait into a 37-day wait, and that’s before any client pays late on top of their own terms (which, according to most small business surveys, happens to roughly half of invoices at some point).
My rule now: net 14 for new clients, net 7 for anyone who’s paid late before, and net 30 only for large companies with fixed payment run dates, and even then I ask what day of the month their payment run happens on so my invoice date lines up with it rather than missing it by a day and getting bumped to the following cycle.
The uncomfortable truth about late invoicing
I’ll say the thing most freelance blogs avoid saying out loud: if you’re chasing unpaid invoices constantly, it’s usually not the client’s fault, it’s yours.
Clients don’t wake up planning to underpay freelancers. They respond to whatever signal you give them. Send a scrappy invoice three weeks late with no invoice number, no due date, and a vague description like “consulting work,” and you’ve told the client, without saying it, that you don’t run this like a business. Late, messy invoicing gets deprioritised in a way that a sharp, on-time, professional-looking invoice never does. I’ve tested this myself: the retainer clients I invoice like clockwork on the 1st pay within days. The ones I’ve been sloppy with, even briefly, take noticeably longer to pay every single time afterwards, because I taught them that my invoices aren’t urgent.
If you want to see what a built invoice needs on it (line items, VAT if applicable, payment terms, your business details), this checklist on how to invoice a customer correctly is the one I wish someone had handed me when I was 26 and sending invoices scrawled in a Word document with no invoice number at all.
Building the timing into your workflow so you never have to remember
The freelancers who never chase late payments aren’t more organised people by nature, they’ve built invoicing into a system that doesn’t rely on memory or willpower. Here’s the version I use:
- Deposit invoice goes out the same day a proposal is signed, not “before we start” as a vague idea, but literally attached to the confirmation email.
- A recurring calendar reminder on the 1st of every month for retainer invoices, set a year in advance.
- A template with all your standard fields already filled in (business name, address, payment details, standard terms) so the only thing left to add is the line items and the date, cutting invoice creation down from twenty minutes to under three.
- One invoicing tool, used consistently, rather than switching between a Google Doc one month and PayPal the next. If you do use PayPal for smaller clients, this walkthrough on how to invoice someone through PayPal covers the fee structure and timing quirks that catch people out. And if you’re still using a template, this piece on filling in a Google Docs invoice template correctly fixes the numbering chaos that makes a lot of freelance invoices look amateur even when the work itself was excellent.
One more thing worth knowing before you get into a dispute with a client: an invoice and a receipt are not the same document, and mixing them up can delay payment or cause tax headaches. If you’re ever unsure which one you should be sending, this breakdown of invoices versus receipts clears it up in about two minutes.
A quick timing checklist for your next job
- Deposit due before work starts: yes or no, decided before you accept the job.
- Milestone invoice needed: only if the project runs longer than two to three weeks.
- Final invoice sent: same day as final delivery, not on sign-off.
- Retainer invoice date: fixed and calendared, ideally the 1st of the month.
- Payment terms: net 14 for new clients, net 7 for repeat late payers, net 30 only for large companies with confirmed payment run dates.
None of this is complicated. It just requires treating the invoice as part of the deliverable, not the paperwork that happens after it. The work isn’t finished until the invoice for it is sent, and the sooner you build that into how you close out a job, the fewer awkward chasing emails you’ll ever have to write again.
Frequently asked questions
Should I invoice before or after I finish the work?
For any project over a few hundred pounds, invoice a deposit before you start and the final invoice the same day you deliver the finished work, not days or weeks after.
How soon after finishing a job should a freelancer send an invoice?
Within 24 hours of delivery is the standard I’d recommend. Waiting longer gives the client time to forget the work happened or reallocate the budget elsewhere, which is exactly what cost me a full-price payment on a workshop I invoiced five weeks late.
Is it unprofessional to ask for a deposit before starting freelance work?
No, it’s standard practice for anything over a day or two of work. Most established freelancers ask for 30 to 50 percent upfront, and a client who refuses to pay any deposit at all is often a warning sign about how the rest of the project will go.
Should I invoice monthly or per project for retainer clients?
Monthly, on a fixed date such as the 1st, invoiced for the previous month’s work. A predictable date trains the client to expect and process your invoice quickly, rather than treating it as a one-off surprise each time.
