How to send an invoice
Who to address it to, what to write in the email, why PDF and not Word, and what to send when nothing comes back. Includes the wording, ready to copy.
An invoice that is written but badly delivered is an invoice that is late. Most payment delays are not disputes about the work — they are documents that reached the wrong person, arrived in a format nobody could file, or were simply never chased. All three are avoidable, and none of them require software to fix.
Send it to the person who pays, not the person who hired you
This is the single most common reason an invoice sits untouched, and it is invisible from your side: the invoice was sent, it was received, and nothing happened, because the person holding it has no authority to pay it.
In anything larger than a handful of people there is an accounts payable
function — sometimes a department, sometimes one person, sometimes an inbox
called invoices@. Your contact is the person who wanted the work.
They are usually not the person who releases money, and an invoice sitting in
their inbox is waiting on them to remember to forward it.
Ask once, at the start of the relationship, before there is anything to chase. One sentence does it:
Before I send my first invoice — which address should invoices go to, and do you need a PO number or reference on them?
Two things come back. The address, which you then use every time. And the reference, which matters more than it sounds: in many companies an invoice arriving without the purchase order number it was raised against cannot be matched to anything, and gets rejected without ever being read. Asking takes a sentence. Discovering it after thirty days of silence costs a month.
When you do send, put your contact in CC rather than dropping them. The accounts team pays it; your contact is the one who can tell them to hurry.
Attach a PDF — and only a PDF
The format is not a matter of taste. Each alternative fails in a specific way:
- A Word or Google Docs file looks editable, because it is. An invoice a recipient can change is an invoice their auditor will question, and some finance teams reject them on sight.
- A photo or a screenshot cannot be searched, filed or read by the software that scans incoming invoices. It also reads as improvised.
- A link with no attachment asks the recipient to visit a site and download something in order to pay you. Some corporate mail filters strip those links entirely, and the invoice never existed as far as the recipient is concerned.
- The invoice pasted into the email body has nothing to file. Accounts payable needs a document, not a message.
A PDF is fixed, universally readable, and small enough that no filter drops it.
Name the file so it means something after it is saved —
INV-014-AriaStudio.pdf, not invoice.pdf. It will land in
a folder with several hundred others.
Sending a link as well as the PDF is fine, and is how most invoicing tools work: attachment for their records, link so they can pay without printing anything.
The email itself
The email is not the invoice. Its only job is to make the attachment easy to act on. Short is better than warm.
The subject line
It will be read in a list of forty. Put the identifying facts in it, in the order somebody searching would type them:
Invoice INV-014 from Aria Studio — due 5 September
That subject survives being forwarded, filed and searched for six weeks later. "Invoice" alone does not, and "Hi!" is how an invoice gets lost.
The body, in full
Hi Nino,
Invoice INV-014 is attached, for the brand identity work completed in August — 1,200 GEL, due on 5 September.
Bank details are on the invoice. If you need a PO number added or it should go to a different address, tell me and I will reissue it.
Thanks,
Levan
Four elements, and nothing else: the number, what it is for, the amount, the date it is due. The second paragraph is doing quiet work — it invites the two corrections that otherwise cause a silent rejection, and it does so before anybody has to admit there is a problem.
What to leave out
"Please find attached" tells the reader nothing they cannot see. Apologising for sending an invoice — "sorry to bother you", "just following up on this" — frames payment as a favour rather than the agreed terms. Long descriptions of the work belong on the invoice, as line items, not in the email. And never write "payment would be appreciated at your earliest convenience": it has no date in it, so it cannot be late, so it will not be paid.
What to send when nothing comes back
Silence is the normal state of an unpaid invoice, and it usually means the invoice is in a queue rather than that anyone has decided not to pay. Chasing is routine administration. Doing it on a schedule you decided in advance stops it being a decision you have to make while annoyed.
A sequence that works, counted from the due date:
Day 1 after due — the assumption of oversight. The invoice is one day late and almost certainly nobody has looked at it.
Hi Nino — invoice INV-014 (1,200 GEL) was due yesterday, so I am resending it in case it needs anything from me. Let me know if it is stuck anywhere.
Day 7 — ask a question instead of repeating yourself. Repeating the same message trains people to ignore it. A question needs an answer.
Hi Nino — INV-014 is now a week past due. Can you tell me whether it has been approved for payment, and if not, what it is waiting on?
Day 14 — go around, politely. Reply to your original email so the whole thread is visible, and add accounts payable if you have not already.
Adding the accounts team here. INV-014 (1,200 GEL, dated 21 August) is two weeks past due — could someone confirm it is in the payment run?
Day 30 — state what happens next. Not a threat; a date.
INV-014 is thirty days past due. Please can this be paid by 5 October. If there is a problem with the invoice, I would rather fix it than keep sending reminders — but I do need to know either way.
Two things make this work. Every message contains the invoice number and the amount, so nobody has to go looking. And every message names a date. Late payment interest, where your law allows it, belongs after this point and not before — mentioning it in the first reminder reads as hostile and rarely accelerates anything.
How to know it arrived
Read receipts do not answer this. Most mail clients let the recipient decline them silently, many corporate systems strip the request, and asking for one on a first invoice reads as distrust.
What tells you something real: a link in the email that the recipient clicks in order to view or pay the invoice. A click is a person. It does not prove they intend to pay, but it does end the question of whether it arrived, and it moves the conversation from "did you get it" to "when will it be paid".
Treat open tracking as much weaker evidence than it looks. Some mail clients fetch images automatically the moment a message is delivered, so an open can mean nothing more than that the message landed.
When they say they never received it
Sometimes true, often not, and it does not matter which. Resend it the same day, reply-all on the original thread so the timestamps are visible, and attach the same PDF.
Do not issue a new invoice number. A resent invoice is the same invoice, and giving it a fresh number creates a second document for the same debt — which is how the same work gets paid twice, or, more often, how a gap appears in your sequence that an auditor will ask about. Numbers must be unique and unbroken; see invoice numbers for why a gap is the part that causes trouble.
If the due date has already passed, the due date does not reset. The invoice was issued when it was issued.
What you are entitled to charge when it is late
Most guides to sending an invoice stop at "send a polite reminder". In much of the world you have statutory rights the moment a commercial invoice is late, and they exist whether or not your contract mentions them — which changes what the day-30 email can say.
| Where | Interest you may charge | Fixed compensation | Default terms |
|---|---|---|---|
| UK | 8% above the Bank of England base rate | £40 up to £999.99; £70 to £9,999.99; £100 above that | Late 30 days after the invoice or delivery, whichever is later |
| EU | At least 8 points above the ECB reference rate — 10.40% for the second half of 2026 | €40 minimum, per invoice | 30 days; agreed terms usually capped at 60 for business-to-business |
| US | Whatever your contract says, within your state's usury cap | None by statute | None — silence means no late fee at all |
Two practical consequences. In the UK and the EU you do not need permission to charge interest — so "this invoice is now accruing statutory interest at 8% above base" is a statement of fact rather than a threat, and it is noticeably more effective than asking again. In the US the opposite is true: with nothing in the contract you have nothing to charge, so the late-fee clause has to be agreed before the work starts, not invented afterwards.
Most freelancers never actually invoice the interest. It is still worth knowing, because a client's accounts department certainly knows, and an invoice that mentions it moves up a payment run.
Rates change every six months. Check the current figure before you put a number in an email, and treat this as orientation rather than legal advice.
When the answer is not silence
Some replies need a different move than another reminder.
| They say | What it usually means | What to do |
|---|---|---|
| "We never received it" | Filed, forwarded, or filtered | Resend the same day on the original thread, same number, same due date |
| "We already paid this" | Often true, and paid against a different reference | Ask for the date and the amount, not for proof — it is faster and less adversarial |
| "It is in the next payment run" | Real, and usually accurate | Ask which date that run is. A named date is a commitment; "soon" is not |
| "There is a problem with the invoice" | A missing PO number nine times in ten | Ask what specifically. Fix and reissue with a credit note, not a silent edit |
| Nothing, from anyone, twice | Your mail is not reaching a person | Phone. One call at day 30 outperforms four more emails |
Before you hit send
The whole thing, as a list to run down:
- It is going to the address accounts payable actually reads, with your contact in CC.
- The PO number or reference they asked for is on the invoice itself.
- It is a PDF, named so it still means something in a folder of four hundred.
- The invoice number is unique and continues your sequence — see invoice numbers.
- The subject line carries the number, your name and the due date.
- The email body names the amount and the due date, and nothing else.
- Bank details are on the invoice, not in the email, and you have read them twice.
- You know what you will send on day 1, day 7, day 14 and day 30 — before you need to.
Sending it without any of this
Everything above assumes you have an invoice, a PDF and an email client. If you do not, the whole sequence collapses into one step: describe what you want on the invoice, and send it from the page you are reading about.
The free invoice generator writes the invoice, calculates it, produces the PDF and emails it to your client — no account, no card and no watermark on the result. If you are not sure what belongs on it yet, start with what an invoice has to contain, or how to write one field by field.