Send a professional quotation that states what is included, what it costs and how long the price holds — then convert it to an invoice once it is accepted.
Stating how long the price holds is what separates an offer from a guess — and it protects you if costs move.
A quotation states what you will deliver and what it costs. Once the client accepts it, that price is the price — which is why the two details people most often leave out matter so much: what exactly is included, and how long the figure stands.
The validity period is not a formality. Materials costs move, currency rates shift, and a quote left open for six months becomes a loss the moment it is accepted. Stating that the price holds for 30 days protects you, and it also nudges the client toward a decision instead of letting the proposal sit unanswered.
Scope is the other half. A quote that says "website redesign — 4,000" invites a dispute the moment the client asks for one more page. Itemise the major deliverables and note what is excluded, so a scope conversation stays a conversation rather than becoming an argument about what was promised.
When the client accepts, the same figures move straight into an invoice — the fields carry across, so you are not retyping numbers and introducing an error between the quote and the bill.
A quote is a fixed price you commit to for a defined scope. An estimate is an informed approximation that may change as the work progresses. Quotes bind you; estimates signal uncertainty.
Thirty days is the most common commercial period. Longer validity exposes you to cost movements, shorter periods pressure the client. If your costs are volatile, use a shorter window and say why.
An accepted quotation forms a contract on its stated terms, so the wording matters. State the scope, price, validity period and payment terms clearly, and have anything high-value reviewed by a professional.
Show whether the price includes or excludes tax, and state the rate. Ambiguity here leads to disputes at invoicing time, particularly on cross-border work where the treatment may differ from the domestic case.