Why using the right document matters
Mix them up and it costs real money: a quotation without a validity period lets a client hold you to a three-month-old price; an invoice without terms makes "pay whenever" the de facto term; no receipt on a cash job turns "I already paid" into your word against theirs. Each document below takes a minute to make, each dispute it prevents takes weeks to resolve.
The three documents side by side
QUOTATION
Before the job
"This is what it'll cost"
"This is what it'll cost"
INVOICE
After the job
"This is what you owe"
"This is what you owe"
RECEIPT
After payment
"Paid, thank you"
"Paid, thank you"
Three documents, three moments, use the right one each time.
| Quotation | Invoice | Receipt | |
|---|---|---|---|
| Purpose | Offer a price | Request payment | Prove payment |
| When | Before work starts | After work is agreed / done | After money arrives |
| Asks for money? | No. Asks for a decision | Yes | No. Confirms it |
| Has an expiry? | Yes. Validity period | No. But has a due date | No |
The normal flow, step by step
- Quote. Client asks "how much?", you send a quotation with a validity period.
- Accept. Client agrees (signature, or "ok proceed" on WhatsApp, keep it in writing).
- Do the work. The accepted quotation is your scope reference.
- Invoice. Request the advance or the full payment.
- Receipt. Money arrives, issue a receipt, ganna.lk's invoice maker has a receipt mode.
Common shortcuts that are perfectly fine
- Immediate payment: skip the separate receipt, an invoice stamped "PAID" with the date does both jobs.
- Small cash jobs: a receipt alone can suffice, though an invoice gives you better records.
- Repeat orders from the same client: you can often skip the quotation once the price list is agreed, invoice directly against the standing prices.
The paperwork should serve the business, not the other way round. Use the full flow where money or scope is significant; collapse it where it isn't.