When to send an invoice as a self-employed person
When to send an invoice when you're self-employed? My answer: the same day you finish the job. Here's why waiting costs you, and what UK law says about it.
When should you send an invoice if you're self-employed? The same day you finish the job. I'd say that's the right answer in nearly every case, and I think most sole traders get it wrong.
Not because they're lazy. Because invoicing feels like a chore, and chores wait until Friday. Then Friday becomes next week.
Here's my argument for doing it today.
The clock doesn't start until the invoice exists
Say you're a self-employed cleaner. You finish a deep clean on Monday. You send the invoice the following Monday, because the weekend got busy.
You've just handed the customer a free week. Nothing was wrong with the work. You simply started the clock late.
GOV.UK explains how the clock works. If you haven't agreed a payment date with a business customer, the payment is late 30 days after the customer receives the invoice, or 30 days after you deliver the goods or service, whichever is later. So if the invoice goes out late, the "whichever is later" part is the invoice date. Every day you wait pushes your money back one day.
The same page says that if you do agree a date, it can usually be within 60 days for business transactions. A longer period is allowed, but it "must be fair to both businesses". So the date you write on the invoice, and the terms you agreed before, matter more than most people think.
Customers pay when the job is fresh
There's a human side to this too. On the day of the job, the customer remembers it. The house is clean. The lesson went well. The haircut looks good.
A week later, that glow has faded. Two weeks later, the invoice feels like a bill from the past. It's the same amount, but it's harder to pay without a second thought.
I'm not citing a study for this. It's my own view: fresh jobs feel easier to pay than stale ones.
Late payment is common, so don't add to it
London Economics researched this for the Department for Business and Trade and the Small Business Commissioner. Their findings, published on 31 July 2025, say that over 1.5 million businesses, or 28% of businesses, are affected by late payments each year. They estimate businesses are owed about £26 billion in late payments at any given time, an average of £17,000 per business affected.
Your numbers will be far smaller. The pattern is the same, though. Someone owes you money and you have to ask for it.
You can't control your customer's habits. You can control when you hit send. It's the one part of the process that's fully in your hands.
What if the customer wants to pay later?
Fair question. Some customers, like a small company, will tell you they pay on a monthly run. That's fine. Send the invoice the same day anyway.
The rule is simple. Agree the terms before you start, and send the invoice as soon as the work is done. If the customer says "30 days", write the real date on the invoice. For a job finished on 25 October 2026, that's 24 November 2026. Not "30 days". A date.
If you don't set terms, the 30 day rule from GOV.UK applies. If you want to know what you can charge when someone does pay late, I covered that in late payment interest in the UK. GOV.UK says statutory interest is 8% plus the Bank of England base rate for business to business transactions, unless your contract sets a different rate.
When I'd wait
There are two cases where I'd hold off.
- The job isn't finished. If you're doing stage payments, invoice at each stage, on the day you hit it. A deposit is the same: send it when the booking is confirmed. I wrote about that in should I take a deposit.
- The customer asked for a specific format. Some larger businesses need a purchase order number on the invoice. Get that first, or the invoice will bounce back and you'll lose the time anyway.
Everything else can go today.
How to make same-day invoicing easy
The reason people delay isn't the job. It's the setup. You have to open a template, type the details, export a file, find an email address and send it.
So cut the steps. Use a template with your details already in it. Write the invoice before you leave, on your phone if you can. If you aren't sure what goes on one, my guide on how to write an invoice as a sole trader lists what GOV.UK requires.
Then add a way to pay. A bank transfer link or a payment link means the customer can pay the moment they read it. No hunting for your sort code.
My take
Send it today. Not tomorrow, not Friday. The invoice is the start of the payment, not the end of the job.
At Vcents, we build for exactly this. You request money in WhatsApp, the customer gets a link and pays from their bank app. It takes about as long as sending a text, which is what makes same-day invoicing realistic.
Sources
Vcents turns the thread into a payment.
Ask for money in plain English. Your customer taps once, authorises in their own bank, and the receipt lands back in the chat.
How receiving payments works