It's a common mix-up for new freelancers: you send an invoice and assume you're covered, or you sign a contract and assume payment will just follow. A freelance contract and an invoice do two different jobs, and understanding the difference is part of what makes a freelance agreement template download worth having before your first invoice ever goes out.
What a contract does
A contract is an agreement about the work itself. It's signed before the project starts, and it covers scope, payment terms, revisions, ownership, and what happens if plans change. Think of it as the rulebook both sides agreed to follow.
What an invoice does
An invoice is a request for payment for work that's already been agreed to — or already completed. It lists what's owed, when it's due, and where to send payment. It doesn't establish what was supposed to happen; it just bills for it.
Why one without the other causes problems
An invoice with no contract behind it has nothing to point to if a client disputes the amount or the scope of what was delivered. A contract with no invoice is just an agreement that's never actually billed — you still need to formally request payment when the work is done. Used together, the contract sets the terms and the invoice enforces them.
Which to send first
Always the contract. Sending an invoice before there's a signed agreement means you're billing for terms the client hasn't formally accepted yet, which makes disputes harder to resolve. The typical order for a new project looks like this: agree on scope in conversation, send the contract, get it signed, do the work, send the invoice per the payment terms already spelled out in that contract.
If you don't have a contract yet, start with the free freelance contract template PDF — it already includes a payment terms clause that your invoice can simply reference. For the full list of clauses to include, see what to include in a freelance contract, or read why a simple contract beats a verbal agreement if you're still deciding whether it's worth the extra step.