Send an estimate when the price can still move, a quote when you are ready to fix it, and a proforma invoice when the client has said yes but you are not yet issuing the real invoice. Picking the wrong one creates price disputes, payment confusion and VAT mistakes.
What is the difference between a quote, an estimate and a proforma invoice?
An estimate gives a rough price range while scope is still uncertain. A quote offers a fixed price for defined work, usually with an expiry date. A proforma invoice previews the final invoice after agreement, in invoice format, but it is not a demand for payment or a VAT invoice.
That one distinction, how certain the price is and how far the sale has progressed, decides which document you need. Everything else in this guide follows from it. If you answer two questions honestly, the choice is usually obvious: do you know exactly what the job involves, and has the client agreed to go ahead?
Settle it in under a minute: uncertain scope means estimate, defined scope with no agreement yet means quote, agreement reached but final invoice not yet due means proforma. Work done means skip all three and send the invoice itself.
| Feature | Estimate | Quote | Proforma invoice |
|---|---|---|---|
| Main job | Give a ballpark so the client can budget | Offer a fixed price the client can accept or reject | Preview the final charges after the client has agreed |
| Price certainty | Low, stated as a range or approximate figure | High, one fixed total for a defined scope | High, itemised to match the expected final invoice |
| When you send it | Early enquiry, scope still moving | After you understand the requirements | After acceptance, before delivery, payment in advance or customs paperwork |
| Client commitment | None, it is guidance only | Forms the agreed price once accepted, subject to your terms | Shows commitment to the sale, but is not itself a payment demand |
| Is it a VAT invoice? | No | No | No, and it should be labelled as such |
| Record it as a sale? | No | No, not until accepted and supplied | No, keep it out of your sales ledger until the real invoice is issued |
| Typical validity | Short, because costs are not locked in | Commonly 14 to 30 days, stated on the document | Tied to the agreed order, update it if terms change |
| What happens next | A quote once scope is clear | Work starts, a deposit invoice, or a proforma if one is needed | The final invoice, which replaces it |
For how these three sit alongside the documents that follow them, see our guide to invoice vs quote vs receipt, which maps the full chain from first price to proof of payment.
When should you send an estimate?
Send an estimate when you cannot honestly fix a price yet, because hours, materials or scope are still unknown. An estimate tells the client the likely order of cost, often as a range, and makes clear that the final price can move if the job changes or takes longer than expected.
Estimates suit early conversations, before the client has a brief. You have enough experience to give a sensible range, but not enough detail to commit. Saying so in writing protects you, and it protects the client, who can budget without mistaking a guess for a promise.
Write estimates so the uncertainty is visible, not buried in small print:
- Give a range, not a single figure, and say what the range depends on.
- Name your assumptions, for example the number of revision rounds, the materials grade, or access to the site.
- State what would push the price above the range, such as extra pages, structural work or rush delivery.
- Add a short validity note, because supplier prices behind your estimate can change too.
Tip: If a client keeps treating your estimate as a fixed price in emails, correct it in writing straight away and offer to turn it into a quote once the scope is agreed. Silence lets the misunderstanding harden into a dispute.
When should you send a quote?
Send a quote when the scope is clear enough that you will stand behind one fixed price for a set period. A quote lists exactly what is included, the total, any tax on top, and an expiry date. Once the client accepts it in time, that price is the deal, unless the scope changes.
A vague quote invites scope creep, because the client can reasonably claim extras were included. A precise quote does the opposite: it defines the work line by line, states what is not included, and gives you a clean basis for charging more when the client asks for more.
A quote that does its job includes:
- Itemised lines with quantities, unit prices and a clear total.
- Tax treatment, for example whether VAT is included or added.
- A validity date, so you are not held to old prices months later.
- Payment terms and any deposit you require before starting.
- Exclusions and assumptions, written in plain language.
You can build one in minutes with LancerBill’s quote generator, which keeps the itemised lines, totals and validity date in a clean format you can send as a PDF. When the client accepts, the same figures carry forward, so you are not retyping numbers into the next document and risking a mismatch.
Watch out: Never quote a fixed price to win work when you know the scope is guesswork. If hidden problems are likely, estimate first, investigate, then quote. A fixed price built on hope turns every surprise into your cost, not the client’s.
When should you send a proforma invoice?
Send a proforma invoice after the client has agreed to buy, when they need an invoice-shaped document before the real invoice can or should be issued. Common reasons are advance payment arrangements, internal purchase approval, a grant or finance application, and customs paperwork for international shipments.
It looks like an invoice, with seller and buyer details, itemised lines, taxes and a total, but it is a preview, not a demand for payment. Label it clearly as a proforma invoice. HMRC’s VAT trader records manual (VATREC9020) is explicit that a proforma is not acceptable evidence for reclaiming input VAT, and that if you later receive payment or make the supply, a full VAT invoice must be issued within 30 days under the normal tax point rules. Rates last reviewed: October 2026.
Your client cannot reclaim VAT on a proforma, and you should not record one as a sale or as money owed. Keep proformas separate from your invoice sequence, with no invoice number. When the work is supplied or payment is received, issue the real invoice with its own number and date.
If the client simply wants to agree a price, a quote is clearer. If the work is done and payment is due, you need the invoice itself. Our guide on how to write an invoice covers what that final document must contain.
Worked example: one job, three documents
Here is the same project passing through all three documents, so you can see how the numbers and the certainty change. Assumptions: a UK freelance web designer, VAT-registered, charging 60 pounds per hour, tax year 2026/27, quoting a small business website.
Stage 1, the estimate. At the enquiry call, the client wants “a new website” but has not decided on pages, copy or booking features. The designer estimates 28 to 36 hours of work plus 200 pounds of copy editing help:
- Low end: 28 hours x 60 = 1,680, plus 200 = 1,880 pounds plus VAT.
- High end: 36 hours x 60 = 2,160, plus 200 = 2,360 pounds plus VAT.
- The client is told, in writing, to budget between 1,880 and 2,360 pounds plus VAT, depending on the final page count and features.
Stage 2, the quote. After a scoping call, the job is fixed at 5 pages, no booking system, 2 revision rounds. The designer quotes a fixed price:
- Design: 12 hours x 60 = 720 pounds.
- Build: 18 hours x 60 = 1,080 pounds.
- Copy editing: 200 pounds.
- Subtotal: 720 + 1,080 + 200 = 2,000 pounds.
- VAT at 20 percent: 2,000 x 0.20 = 400 pounds.
- Total: 2,400 pounds, valid for 30 days, with a 50 percent deposit before work starts.
Stage 3, the proforma. The client accepts the quote. Their office manager needs an invoice-format document to raise a purchase order and release the deposit, but no work has been supplied yet. The designer sends a proforma showing the same lines and the 2,400 pound total, clearly marked “Proforma invoice, this is not a VAT invoice”. No sale is recorded.
Stage 4, the real invoices. The client pays the 1,200 pound deposit. That payment triggers the need for a proper VAT invoice for the deposit amount, issued within 30 days. On launch, the designer issues the final invoice for the 1,200 pound balance using LancerBill’s invoice generator, converting the agreed quote figures rather than retyping them. Total invoiced across both invoices: 1,200 + 1,200 = 2,400 pounds, matching the quote exactly.
Each document did one job, then handed over to the next. For deposit structures like this one, see our guide on how much deposit to ask for upfront.
A decision framework: which document in 30 seconds
Most guides stop at definitions. In practice you are usually mid-conversation, with a client waiting, so use these four questions in order. The first clear answer wins.
| Question | If yes | If no |
|---|---|---|
| 1. Is the work done, or is payment now due? | Send an invoice, not any of these three | Go to question 2 |
| 2. Has the client already agreed to buy at an agreed price? | Proforma, but only if they need an invoice-format preview for approval, advance payment admin or customs | Go to question 3 |
| 3. Can you fix the price from a defined scope? | Send a quote with a validity date | Go to question 4 |
| 4. Can you give a sensible range from experience? | Send an estimate with assumptions and a range | Ask more questions or charge for a scoping session first |
Two edge cases come up often. Some corporate clients call everything a quote, including proformas, because their finance team needs an invoice layout for approval. Send the format they need, but keep your label accurate, because VAT treatment follows the document type, not the client’s nickname. And for export orders, buyers and customs brokers routinely ask for a proforma before shipment to arrange import paperwork and payment, a genuine proforma use.
Estimate the unknown, quote the known, proforma the agreed, invoice the supplied.
Common mistakes that cause disputes
Calling a guess a quote. The word on the document sets expectations. If the price can move, do not label it a quote, however much the client pushes for “just a quick quote”. Give an estimate and say what information would turn it into a fixed quote.
No expiry date on quotes. Material and subcontractor prices change. A quote accepted nine months later at old prices can erase your margin. Put a validity period on every quote and honour it, then re-quote without embarrassment once it lapses.
Booking a proforma as income. A proforma is not a sale, not a receivable and not VAT evidence. Posting it to your ledger overstates revenue and can create a tax mess, and if your client also files it, they may try to reclaim VAT they are not entitled to yet. Convert it to a real invoice at the right moment and file the proforma as supporting paperwork only.
Paying against the wrong document. If a client pays, make sure a real invoice follows promptly, and use a receipt generator to document the payment received. Do not leave a proforma as the only paper in the file.
Sending all three for one small job. For a small job with clear scope, a quote followed by an invoice is enough. Extra documents slow approval and confuse clients.
Key takeaways
- An estimate is a range for uncertain scope, a quote is a fixed price for defined scope, and a proforma invoice is an invoice-format preview after agreement.
- None of the three is a VAT invoice. Per HMRC VATREC9020, a full VAT invoice must follow within 30 days once payment is received or the supply is made.
- Put a validity date, itemised lines and exclusions on every quote, and name the assumptions behind every estimate.
- Keep proformas out of your sales ledger and invoice numbering, and convert them to real invoices at the right tax point.
- Use the 30-second framework: invoice if payment is due, proforma if agreed and a preview is needed, quote if you can fix the price, estimate if you can only give a range.
Once you have decided a quote is the right document, our guide on how to write a quote for a job covers what to include, how to price it and how long to keep it valid.
Frequently asked questions
Is a quote legally binding once a client accepts it?
An accepted quote generally forms the price term of your agreement, so you should expect to honour that fixed price for the defined scope within its validity period. The wider contract still depends on your terms and the circumstances, so put terms in writing. This guide is general information, not legal advice.
Can a client pay against a proforma invoice?
Clients often arrange payment, especially deposits, using a proforma as the reference document. The proforma itself is not a VAT invoice or a formal demand for payment, so once payment is received you must issue a proper VAT invoice within 30 days if you are VAT-registered, following HMRC tax point rules.
Can I charge more than my estimate?
Yes, if the estimate was clearly presented as approximate and the extra cost comes from scope changes or factors you flagged. Tell the client as soon as you see the price moving, not on the final invoice. If the document was a fixed quote for the same scope, charging more is much harder to justify.
Does a proforma invoice need an invoice number?
No. A proforma should not take a number from your sequential invoice sequence, because it is not an invoice. You can give it its own reference, such as a quote or order reference, so you can file and trace it without creating a gap or a duplicate in your invoice numbering.
How long should a quote be valid for?
Fourteen to 30 days is typical for freelance services. Shorter periods suit work priced on volatile materials, longer periods suit stable, labour-only work. Whatever you choose, print the expiry date on the quote itself, so there is no argument about which prices applied when the client accepted.
Should I send an estimate or a quote for a first enquiry?
Send an estimate if you do not yet know the hours, materials or scope well enough to fix a price. Once a short scoping conversation has pinned those down, follow up with a fixed quote. Sending both, in that order, is normal practice and shows the client the price firming up as the details do.
This guide is for general information only and is not financial, tax or legal advice.