A quote is sent before work begins to show what you will charge. An invoice is sent after the work is done to request payment. A quote is an offer; an invoice is a demand. If a client accepts your quote, you complete the work and then issue an invoice for the agreed amount.
What is a quote?
A quote (also called a quotation or proposal) is a document you send to a prospective client before doing the work. It sets out:
- What work you will do
- What it will cost
- How long the quote is valid
- Any terms and conditions
A quote is not a request for payment. It is an offer that the client can accept, negotiate, or decline. The quote becomes binding only when the client formally accepts it.
Quotes typically have an expiry date (such as “valid for 30 days”) to protect you from clients accepting an old quote after your costs have changed.
What is an invoice?
An invoice is a document you send after completing the work (or in some cases, during or before the work if a deposit is required). It formally requests payment for goods or services delivered.
An invoice typically includes:
- Your business details and the client’s details
- A unique invoice number and date
- A description of what was delivered
- The amount owed
- The payment due date
- Your banking details or payment link
If you are VAT registered, your invoice is specifically a “tax invoice” with additional SARS-required fields. See What is a Tax Invoice in South Africa?
Quick answer
What is the difference between a quote and an invoice in South Africa?
A quote (or quotation) is sent before work begins to show a client what you will charge. It is an offer that the client can accept, negotiate, or decline. An invoice is sent after the work is complete (or at an agreed milestone) to formally request payment. In South Africa, quotes typically include a validity period (such as “valid for 30 days”) to protect against acceptance after costs change. Once a client accepts a quote, you complete the work and issue an invoice for the agreed amount. The invoice amount should match the accepted quote unless additional scope was agreed. Rebill lets you convert accepted quotes to invoices with one click, automatically populating all the details from the original quote.
Side-by-side comparison
| Feature | Quote | Invoice |
|---|---|---|
| Sent when | Before work begins | After work is complete (or at deposit stage) |
| Purpose | Offer/estimate | Payment request |
| Payment required? | No | Yes |
| Can be declined? | Yes | No (it is a demand, not an offer) |
| Expiry date | Usually yes | Usually no (has a payment due date instead) |
| VAT required? | Optional (if applicable) | Yes (for VAT vendors) |
| Legal status | Becomes binding on acceptance | Legal payment demand |
When should you use a quote?
Use a quote when:
- The project scope or cost is not fixed and the client needs to approve the price before you begin
- The work is significant and the client expects a formal approval process
- You are working with a new client who wants to compare prices with other suppliers
- The client or their company requires quotes as part of their procurement process
When should you use an invoice without sending a quote first?
For repeat clients with agreed rates, you often skip the quote and go straight to an invoice. Examples:
- Monthly retainer clients who have already agreed on a fixed fee
- Service calls where the price is agreed over the phone
- Standard products or services with published prices
Converting a quote to an invoice in Rebill
Rebill lets you convert an accepted quote to an invoice with one click. All the line items, amounts, and client details from the quote are automatically transferred to the invoice. You do not need to re-enter anything.
The quote is marked as “converted” and the invoice is created with a new invoice number and the current date. You can add any additional charges (such as extra work not in the original scope) before sending.
What if the client wants to change the scope after accepting a quote?
If the client requests additional work beyond the accepted quote, you have two options:
- Issue a separate invoice for the additional work
- Issue a revised quote for the client to approve before proceeding with the additional work
The second option is cleaner for larger scope changes. The first is common for small additions where the client has already verbally agreed.
Frequently asked questions
Is a quote legally binding in South Africa?
A quote is not legally binding until the client accepts it. Once accepted (in writing, verbally, or by conduct such as paying a deposit or directing you to begin work), the quote becomes a contract. The terms of the accepted quote govern the work. If the client tries to change the terms after acceptance, this is a contract renegotiation, not a rejection of the original quote.
What is the difference between a quote and a proforma invoice?
A proforma invoice is essentially a formal estimate that looks like an invoice but is not yet a payment demand. It is used in some industries (particularly import/export and corporate procurement) as a preliminary document before the actual goods or services are delivered. A quote serves a similar purpose for service businesses. The main difference is that proforma invoices are typically used in trade contexts, while quotes are more common in service businesses. Both are replaced by a proper invoice once the work is done.
How long should a quote be valid for?
Most South African service businesses set quotes valid for 14 to 30 days. This gives clients reasonable time to consider but protects you from clients accepting a months-old quote after your costs or rates have increased. If a client accepts after the validity period, you have the right to reissue a new quote with updated pricing. Always state the validity period clearly on the quote document.
Can I invoice more than the quote if costs increase?
Generally, no, without the client's approval. An accepted quote is a contract. If your costs increase after acceptance, the appropriate step is to inform the client and agree on a revised amount before completing the work. Surprising a client with a higher invoice than the accepted quote damages trust and can result in a disputed payment. For projects with genuine cost uncertainty, include a contingency in your quote or add a clause allowing for variation with written client approval.