A WooCommerce waiver can be signed at one of two moments. Before payment, where the customer signs on a page of your own site and the checkout will not place the order until it is signed. Or just after the order, where the agreement is started when the order is paid or placed and offered on the thank-you page, in the order email and under My Account. Either records more than a terms tick box does. Which timing suits a shop depends mostly on what should happen if somebody never signs.
Which shops need a WooCommerce waiver, not just a terms box
Any shop where the thing being bought happens after the sale, and happens to a person. Rentals: a kayak, a trailer, a set of skis. Tours and charters. Classes, from pottery to climbing. Events with a physical side to them. A booking for a party of six that one person pays for.
What these have in common is that the risk is not in the transaction. It is on the water, on the wall or on the road, days later, and the person on the wall may not be the person whose card paid for it.

A terms tick box and a signed waiver record different things
WooCommerce can link your terms and conditions at checkout, and the checkout block has a setting that requires a tick in the box before the order goes through. That is a sensible home for a shop's general terms, and it records roughly what it looks like: an order was placed from a checkout that would not continue without a tick.
A tick box is not built to answer the questions a waiver gets asked later. Which version of the terms was on the page that afternoon. Whether the customer agreed to sign electronically, as a step of its own. Whether a fingerprint of the exact text was kept with the agreement, so that a later edit to the terms page would show. What the customer took away. And whether the person who ticked is the person who went out on the water.
A signed WooCommerce waiver is built for those questions: the document as it was shown, the agreement to sign electronically recorded before the signature, the name typed, the time and where from at each step, a fingerprint of the text, and a copy for the signer.
Signed before payment
This is the strict version of a WooCommerce signature at checkout. With Before payment chosen, a customer whose cart holds a product that needs an agreement is sent to a page of your site, drawn in your theme, that lists what the cart needs signed. For the first one it asks who is signing, a name and the email address the signed copy goes to, and then shows SignSealer's signing page in a frame on that same page.
The frame is worth a paragraph, because SignSealer's signing pages normally refuse to be framed at all. A signing page inside somebody else's site is a clickjacking target, and the thing being clicked is a signature. So a business's signing pages may be framed only on sites that business has proven it holds: a signing domain it verified, a proven company sign-in domain, or the site where it connected an app, which is how the WordPress site you connected qualifies. Everywhere else the answer is still no. A browser that will not show the frame is offered the same link in a new tab.
The checkout, classic and block alike, then asks SignSealer whether the customer's own signature is done, rather than trusting anything the browser says, and refuses to place the order until it is. This is how you require agreement before a WooCommerce order exists. The order that follows carries the signed document, with a note saying it was signed at checkout, before payment.
The trade-off: you never take money for something the customer has not agreed to, which for a charter or an equipment hire is the point. The cost is one more step between the cart and the payment, and some people leave at every step. An agreement started and never finished costs nothing, because a signing is counted when it is completed.
Started when the order is paid or placed
The other two choices start the agreement after the order exists: When the order is paid, or As soon as the order is placed, paid or not, which suits a shop where payment comes later, such as a rental paid at the dock. The customer is offered the agreement with a Sign now button on the thank-you page, in their order email and under My Account, and after signing is offered the way back to their order.
Here the trade-off runs the other way. The checkout stays exactly as short as it was, and nobody abandons a cart over a waiver. But the order is complete whether or not the agreement ever is, so somebody has to look. The SignSealer box on the order screen shows each agreement and where it stands, and the order notes say when it was sent and when it was signed. An order with no email address has nowhere to send one, and a note on the order says so.
The rule of thumb in the plugin's own guide: paid for most shops, placed when payment happens later, and before payment when you must not take money for something the customer has not agreed to.
WooCommerce Bookings: the agreement starts on confirmation
A bookable product is marked the same way as any other. What WooCommerce Bookings adds is a moment of its own: a booking you confirm starts its agreement straight away, whether or not it has been paid, because a booking that needs confirming can sit unpaid for days and the agreement is wanted before the day, not after the card.
The booking's details go into the template as blanks: the date, the time, the number of people and the resource, as booking_date, booking_time, persons and resource. So a WooCommerce Bookings rental agreement arrives already saying which boat, which Saturday and how many aboard, and the booking's own screen shows where it stands. The WooCommerce Bookings guide has the steps.
One agreement per product, and what that means for groups
It is worth being clear about the limit. The plugin starts one agreement for each product in the order that needs one, sent to the person who placed the order, with the quantity and, for a booking, the number of people available as blanks. It does not send each member of a party a link of their own, and it does not route a minor's form to a guardian.
That matters because a signature is attributed to the person who gave it. Six adults on one order are six people, and one person signing once attributes nothing to the other five. A guardian signing for a child is doing something different again; minors, guardians and group signing goes through why. If each participant has to sign their own, the order's agreement is the booker's, and the rest of the party needs a way in of their own, such as a Sign now button on a page you send them to, where each fills in their own name and signs. Those signatures are kept in SignSealer rather than on the order.
Setting it up
Once the site is connected, a WooCommerce waiver is three steps: on the product's General tab choose its SignSealer agreement, under SignSealer → WooCommerce choose when it is signed, and place a test order yourself. It works with the classic checkout and the checkout block, and with orders stored as posts or in WooCommerce's own order tables. The WooCommerce guide walks through each screen, the WordPress plugin page covers connecting the site, and the page on rental agreements is about the document itself.
SignSealer is not a law firm and this is not legal advice. Whether a checkout tick box or a signed waiver is what your shop needs, and what a waiver may say where you operate, are questions for a lawyer or your insurer.

