The short answer
| Quotation | Invoice | |
|---|---|---|
| What it is | An offer to do work at a stated price | A demand for payment for work done or goods supplied |
| When it is sent | Before the work | During or after the work |
| What it asks for | A decision | Money |
| Is it a tax document | No | Yes, once you are VAT registered |
| Does it affect your books | No | Yes — it creates a receivable |
What a quotation does
A quotation sets out the scope and the price so the client can decide. It should always carry a validity period — 7, 14 or 30 days is normal — because your material costs and your availability change. Without an expiry, a client can come back in four months holding you to a price you can no longer honour.
- Scope, itemised, so there is no argument about what is included.
- The price, and whether it includes VAT.
- A validity period.
- Payment terms and any deposit requirement.
- What is expressly excluded.
Is a quote legally binding?
In general terms, a quotation is an offer. Once the client accepts it, you have an agreement on those terms, which is why the wording, the exclusions and the validity period matter. An estimate is different — it signals an approximate figure rather than a firm offer — and it is worth being clear on the document which one you are giving. For anything with real money attached, get the acceptance in writing rather than over the phone.
How the two connect
- You send a quotation with the scope, price and validity.
- The client accepts it, ideally in writing or with a signature.
- You do the work — or invoice a deposit first if there are materials to buy.
- You invoice, referencing the quote, with the same lines and totals.
- The client pays against the invoice.
The step that goes wrong most often is number four: the invoice is retyped from scratch and does not match the quote. Then the client queries it, and payment stalls for a fortnight over a R300 difference.
Where a pro forma fits
A pro forma invoice sits between the two — it looks like an invoice and is often used to request payment up front, but it is not a tax invoice and does not go into your books as a sale.