Two things people believe about contracts in South Africa are wrong, and they're wrong in opposite directions. The first is that nothing counts until it's signed. The second is that a signature makes anything stick.
A contract is an agreement. The signature is just the easiest way to prove one happened.
What the law requires
Strip away the formality and a valid contract needs a handful of things to be true.
There has to be genuine agreement, the meeting of minds: an offer, and acceptance of that same offer. Both parties need the capacity to contract, which is where minors and, in some circumstances, people acting without authority for a company come in. What's agreed has to be lawful and actually possible to perform. The terms have to be certain enough that a court could work out what each side promised. And where a specific formality is required by law, it has to be met.
That last one is short. Most agreements have no required formality at all. The sale of immovable property must be in writing and signed. A handful of other agreements are shaped by specific statutes, from credit agreements to certain long leases. Outside that, the law doesn't much care what form your contract takes.
Notice what isn't on the list. Witnesses, initials on every page, a stamp, formal legal language. None of it is required. The page of "hereinafter referred to as the Party of the First Part" adds nothing that plain words wouldn't.
So why bother writing it down
Because being right and being able to prove it are different problems.
An oral agreement is a real contract, and it's nearly useless in a dispute. You remember a twelve-week timeline, they remember eight. You remember excluding materials, they don't. Neither of you is lying. Human memory reorganises itself around what you wanted to have agreed, which is precisely why written terms exist.
A written contract does three things. It forces you both to be specific while you're still friendly, which surfaces disagreements before they cost anything. It records what was agreed in a form that doesn't drift. And it gives a third party something to read if it ever comes to that.
The specificity part is where the real value sits. Most disputes aren't about bad faith. They're about something nobody wrote down: what happens if the client is slow supplying content, who pays for a site visit that gets cancelled, whether the price included the second revision. Writing it out is what makes you notice the gaps.
Where the signature fits
The signature is evidence. It says: this person saw these terms and assented to them. That's a useful thing to have, which is why we all do it, but it's not the ingredient that makes the contract exist.
This cuts both ways. An unsigned agreement that both sides clearly acted on can bind you. A signed document with terms too vague to enforce, or terms that are unlawful, doesn't become good because someone signed it. And a signature on the wrong version of a document proves agreement to the wrong thing, which is the most common self-inflicted wound in small-business paperwork.
Because a signature is evidence, its worth depends on how well it's tied to a person. A cropped signature image dropped into a PDF is easy to deny. A signing link sent to the client's own number, opened and submitted at a recorded time, is not. Same legal status, very different day in front of a magistrate.
The practical version
Put it in writing, in plain language. Be specific about price, scope, timing, payment terms and what happens when something goes wrong. Get it signed in a way that records who signed and when. Keep the signed version and the record together, and never edit a document after it's been signed. Start a new one.
E·BIZI Papers exists for that last part: build the contract once as a template, email it for signature, and keep the signed PDF with the trail behind it.
This guide covers general principles, not advice on your contract. For anything with real money or a long commitment attached, have someone qualified read it.