Invoice vs Quotation: The Difference Explained
A quotation is a fixed-price offer; an invoice is a request for payment. Understand the legal and practical differences before you send either.
A quotation is an offer
Unlike an estimate, a quotation is a firm price for a defined scope. Once the client accepts it in writing, most legal systems treat that acceptance as forming (or confirming) a contract. You generally cannot raise the price later without agreement. That precision is exactly why quotations must be written carefully: vague scope plus a firm number is how disputes start.
An estimate says "we think it will cost about this." A quotation says "we will do this for this price." An invoice says "please pay this amount for what was supplied."
An invoice is a demand for payment
The invoice comes after acceptance and delivery (or at an agreed milestone). It should mirror the accepted quotation line for line wherever possible. If the totals differ, explain why on the invoice itself and reference an approved change request or variation order. Silent increases destroy trust and slow approval.
Invoices carry due dates and payment instructions. Quotations carry validity periods and acceptance blocks. Do not merge the two into one ambiguous PDF.
Quotation checklist
- Quotation number and date
- Your legal business details and the client's legal details
- Detailed scope of work and explicit exclusions
- Fixed price with tax treatment stated (inclusive vs exclusive)
- Validity period (for example, 14 or 30 days)
- Payment schedule (deposit, milestones, balance)
- Assumptions and dependencies (client assets, access, third-party costs)
- Acceptance signature or written acceptance instruction
Exclusions matter as much as inclusions. If hosting, stock photography, travel, or print are not included, say so. Clients fill silence with optimistic assumptions.
Estimate vs quotation vs invoice
| Document | Price nature | Typical timing | Asks for money? |
|---|---|---|---|
| Estimate | Projection / range | Early scoping | No |
| Quotation | Firm offer | Before work starts | No (until accepted and invoiced) |
| Invoice | Amount due | After supply / milestone | Yes |
For the estimate distinction in more depth, read invoice vs estimate.
Practical workflow
- Quotation: send a firm, numbered offer with a validity window.
- Written acceptance: email confirmation or signed acceptance block.
- Deposit invoice: if your terms require one before work begins.
- Work: deliver against the accepted scope.
- Final (or milestone) invoice: mirror the quote; list variations separately.
- Receipt: confirm payment when funds clear.
Skipping the acceptance step is the single most common cause of scope disputes. A verbal "sounds good" is not enough when money and deadlines are involved. Ask for a short written "We accept quotation Q-2026-018" reply.
Handling changes after acceptance
When the client asks for extras, issue a short written variation (or updated quotation for the delta) and get acceptance again before doing the work. Then invoice the variation as its own line: "Variation V-03: additional landing page, as approved 12 May 2026."
Do not absorb unlimited "small tweaks" without a process. Small tweaks accumulate into unpaid days. Your quotation's revision limit (for example, "two rounds of revisions included") should be visible and enforced politely.
Payment schedules on quotations
Spell out deposits and milestones on the quotation so nobody is surprised when invoices arrive. Example: "40% deposit on acceptance, 40% on design approval, 20% on launch." Each tranche then gets its own invoice with a clear label.
For freelancers, deposits also filter unserious enquiries. The freelancer's invoice guide covers deposit and chase tactics in more detail.
Legal flavour without the lawyer voice
You do not need theatrical contract language on a quotation, but you do need identifiable parties, a description of what is included, a price, a validity window, and a way to accept. Those elements are what turn a PDF into something a mediator can recognise as an offer that was accepted. Keep tone human; keep structure complete.
If your work involves intellectual property assignment, confidentiality, or limitation of liability, point to a master services agreement rather than cramming a novel into the quotation footer. The quotation should stay readable for the person who signs it.
Unit-price quotations vs lump sums
Unit-price quotes such as rate cards, per-page, or per-seat pricing scale with quantity and need a stated estimate of units plus the rule for true-ups. Lump-sum quotes need crisp scope boundaries. Mixing both without labelling which lines are fixed and which are variable is a classic dispute pattern that surfaces only at invoice time.
When you invoice a unit-price job, show actual quantities. When you invoice a lump sum, show the deliverable names from the quote. Familiarity between the two documents speeds approval inside the client's organisation.
Multi-currency quotations
If you quote in one currency and might invoice in another, say how foreign exchange will be handled. Prefer quoting and invoicing in the same currency whenever possible. Mid-project currency switches create unreadable variance between quote and invoice totals even when both parties acted in good faith.
State whether prices are tax-inclusive or tax-exclusive on the quotation so the first invoice does not surprise anyone. Surprises at billing time are rarely forgiven quickly.
When a quotation should expire
Material prices, exchange rates, and your own utilisation change. A 14- or 30-day validity window is not unfriendly. It is honest. When a client accepts after expiry, re-issue or confirm the old price in writing before you schedule work. Honouring expired quotes silently trains late decisions and eats margin.
Put the expiry date near the total where it will be seen, not only in fine print at the bottom of page two.
If you need a ready layout for the quote itself, our quotation format guide walks through every field with a worked sample.
Create the documents cleanly
Keep quotation and invoice numbering in separate series if that helps your filing (Q-2026-018 vs INV-2026-0041), and cross-reference them in notes. When it is time to request payment, build the invoice in the free invoice generator using a layout such as Corporate for formal buyers or Elegant for premium services.
Frequently asked questions
Can I withdraw a quotation after sending it?
In many legal systems, you can withdraw a quotation before the client accepts it, as long as you tell them clearly. Once accepted, it usually becomes binding. The position can differ if you promised to keep the offer open for a set period, or under some countries' laws, so check locally. A clear validity date and a statement that prices are subject to availability give you more flexibility.
Is a quotation the same as a proforma invoice?
No. A quotation is an offer made before the client has agreed to buy. A proforma invoice usually comes after the client has agreed in principle and shows exactly what the final invoice will look like, often so they can pay in advance or arrange import paperwork. Neither is a demand for payment recorded as a sale; that is the role of the final invoice.
Can a client negotiate a quotation?
Yes. If the client proposes different prices or terms, that is usually treated as a counteroffer rather than acceptance. If you agree to the changes, issue a revised quotation with a new version number, such as Q-2026-018-v2, and ask the client to accept that version in writing. That way your invoice can reference the exact version both sides agreed.
What if my costs go up after the client accepts a fixed quotation?
In general, you bear the extra cost, because a quotation is a firm price for the defined scope. You can only raise the price if the client agrees, if the scope changed, or if your quotation included a price adjustment clause, for example for material costs or exchange rates. For long or volatile projects, include such a clause and keep validity periods short.
Does a client have to sign a quotation for it to be accepted?
Not always. In many places, a clear written acceptance, such as an email saying "We accept quotation Q-2026-018", is enough to form an agreement, and sometimes conduct, like asking you to start work, can count too. A signature is stronger evidence and some clients require one. To avoid doubt, state on the quotation how it should be accepted.
Can I invoice the full quoted amount if the client cancels part way through?
Usually only if your terms allow it. Without a cancellation clause, you can normally invoice for work completed and costs already incurred, but not the full price. Many quotations include a cancellation clause that sets fees for cancelling at each stage, or make deposits non-refundable. Put those terms on the quotation so they form part of the accepted agreement.
What is an RFQ?
RFQ stands for request for quotation. It is a document a buyer sends to suppliers asking them to quote for specific goods or services, usually so it can compare prices on the same basis. Respond in the format and by the deadline the buyer sets, answer every question, and include your validity period and terms. If you win, the buyer may issue a purchase order that references your quote.
Can I send an invoice without sending a quotation first?
Yes. Many small or routine jobs are agreed verbally or by email at published prices, and the invoice is the first formal document. A quotation is most useful when the job is large, custom or likely to be disputed. If you skip it, make sure the price and scope were clearly agreed beforehand, so the invoice does not come as a surprise.
Does a quotation turn into a purchase order?
Not directly. The quotation is your offer as the seller. If the client accepts, their purchasing team may issue a purchase order, which is the buyer's own document confirming the order and the price, often referencing your quotation number. You then put the PO number on your invoice. Many large clients will not pay an invoice that does not show a valid PO number.
Do I charge tax on a quotation?
No tax is charged on a quotation itself, because no sale has happened yet. The quotation should simply show how tax will apply, either as a separate estimated line or with a clear statement that prices exclude or include tax. Tax becomes due under your local rules when the supply happens, an invoice is issued or payment is received, depending on your tax system.
Invoice Creator Editorial Team
Guides on invoicing, cash flow and small-business finance from Invoice Creator, operated by Next Software Development Company. Content is reviewed for accuracy against the fields our own invoice generator produces.
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