Quotation vs invoice vs receipt: what's the difference
These three documents get used interchangeably by newer freelancers, but each serves a distinct legal and practical purpose in a transaction — mixing them up creates real confusion for clients and accountants alike.
Quotation (or estimate)
A quotation is sent before any work begins — it's a proposed price for a defined scope, not yet a request for payment. It typically has a validity period ("valid for 14 days") since costs or availability can change. No payment obligation exists yet; it's the client deciding whether to proceed.
Invoice
An invoice is a formal request for payment, issued after work is delivered (or at agreed milestones) — it creates a payment obligation with a due date. Unlike a quotation, an invoice is a legal record with specific compliance requirements if you're GST-registered (invoice number, GSTIN, tax breakdown, etc).
Receipt
A receipt confirms that payment has actually been received — it's issued after the invoice has been paid, as proof the transaction is complete. Some freelancers skip issuing separate receipts and instead mark the invoice itself as "Paid," which is fine for most informal use cases but a dedicated receipt is sometimes specifically requested (as with rent receipts for HRA claims).
Why the distinction matters
- Sending a "quotation" labeled as an "invoice" can confuse a client's accounts team into thinking payment is due before work has even started.
- GST compliance requirements apply specifically to invoices, not quotations — a quotation doesn't need a GSTIN or tax breakdown since no supply has occurred yet.
- Keeping quotations, invoices, and receipts as separate, correctly labeled documents makes your own record-keeping and any later reconciliation far easier.