What is the difference between an invoice and a quotation?

A quotation is sent before the work to get the price approved. An invoice is sent after delivery to request payment. A quotation is an offer; an invoice is a demand for payment.

Can I turn a quotation into an invoice?

Yes. Once the customer accepts the quotation, the same line items, quantities and prices become the invoice. Only the document type, number and dates change.

Do I still need a receipt if I issued an invoice?

Yes. The invoice requests payment; the receipt confirms money was received. Customers often need the receipt for their own records.

Invoice vs Quotation — Which One Do You Send?

The short answer

	Quotation	Invoice
When	Before the work	After delivery or completion
Purpose	Get the price approved	Request payment
Legally	An offer — the customer can decline	A demand for an amount owed
Prices	Can still change	Fixed once issued
Usually numbered	QUO-0001	INV-0001

The full document cycle

Most small businesses in Malaysia use four documents. They are not alternatives — each one marks a different moment.

Quotation — the customer asks "how much?". You send a price. Nothing is owed yet.
Invoice — the customer accepts, you deliver, then you invoice. Now money is owed.
Receipt — the customer pays. The receipt proves you received it.
Credit note — something needs to come off the invoice: a returned item, a wrong quantity, an agreed discount after the fact.

A credit note is not a cash refund and it is not a way to delete an invoice. It records an agreed reduction against an invoice that already exists, so both documents stay in your records and the totals still reconcile.

Turning a quotation into an invoice

Once the customer says yes, the content barely changes. The line items, quantities and prices carry over. What changes is:

The document title — Quotation becomes Invoice
The number — from your quotation series to your invoice series
The dates — issue date, and a payment due date instead of a validity date
Payment instructions — bank details and terms belong on the invoice

Retyping all of this is where mistakes appear. A quantity gets changed, a discount is dropped, and the customer notices the mismatch before you do. Copying the accepted quotation directly into an invoice removes that risk entirely.

Try it in your browser

Create a quotation, then convert it to an invoice without retyping anything. No account, no installation.

Open InvoisLaju

Common questions

Should a quotation have an expiry date?

Yes, if your costs move. Wholesale prices, materials and shipping change. A line like "valid for 14 days" protects you from a customer accepting a three-month-old price.

Can I ask for a deposit before delivering?

Common practice is to issue the invoice, record the deposit as a payment against it, and show the remaining balance due. That way one invoice tracks the whole job instead of two half-invoices that are hard to reconcile later.

Do I need to send a receipt if the customer paid by bank transfer?

You are not always required to, but customers routinely ask for one, and it settles disputes about whether a payment landed. It costs nothing to issue.

What about proforma invoices?

A proforma invoice is closer to a quotation than an invoice: it states an expected amount before delivery, often so the customer can arrange payment or clear goods. It is not a request for payment of a completed sale, and it should not be numbered in your invoice series.

Numbering the two series separately

Keep quotations and invoices on separate number series — QUO-0001 and INV-0001. Mixing them into one sequence means gaps in your invoice numbers, which is exactly the thing that raises questions during an audit or a handover to an accountant.

InvoisLaju — free during the trial

Invoices, quotations, receipts and credit notes in one place. Save customers and products once, reuse them, and export PDF or PNG. Your data stays in your browser.

Create a document now

Invoice vs quotation — which one do you send?