Setup, in six steps and about twenty minutes

Installing asks for two scopes: read and write access to orders, and read access to products if you intend to use the add-products module. SelfServe requests nothing else, and it never asks for customer payment scopes because it has no use for them.

Once installed, open Online Store, then Themes, then Customize, and switch the page selector at the top to Checkout and accounts, then Order status. Add a block, choose SelfServe order editing, and drag it to where you want it. Directly beneath the order summary is the position most merchants pick, because that is where a customer is already reading their own address.

Save the theme. The block will not do anything visible yet, because editing stays off until you finish step six.

In the SelfServe admin, open Settings, then Edit window, and pick one of the presets: one hour, three hours, twelve hours or twenty-four hours. Growth and Scale plans can set any value in that range rather than choosing a preset.

Work out your figure honestly rather than optimistically. If your pickers start at eight in the morning and orders placed overnight are untouched until then, a twelve or twenty-four hour window costs you nothing. If you pick continuously and a label can print eleven minutes after checkout, use one hour and let the fulfilment check do the rest.

The window always closes early when a fulfilment is created, so a generous setting is not the risk it first appears to be. What it changes is how many customers get to fix their own mistake before your team has to.

Under Settings, then Allowed changes, you will find one switch per change type: email address, phone number, recipient name, delivery address, and delivery instructions. Everything is off when you arrive, so nothing goes live by accident.

Start with contact details and delivery address if you are unsure. Between them they account for the large majority of the "can you change my order" messages a store receives, and neither has a pricing consequence for you.

While you are on this screen, set your guard rails. Cap edits per order at three unless you have a reason not to. If you ship internationally, turn on the restriction that keeps address changes inside the original country, so a customer cannot move a domestic delivery abroad at the domestic rate. Add any order tags that should never be editable to the exclusion list, wholesale and subscription being the usual two.

Open Settings, then Add products, and switch the module on. Then choose which products are eligible: either your whole catalogue, or a specific collection, which is the safer starting point.

Exclude anything that would break your packing assumptions. Oversized items that need their own box, fragile goods that ship separately, made-to-order pieces with their own lead time, and anything that changes the shipping class of the parcel are all worth leaving out of the eligible set.

Set the cut-off for additions separately from the main edit window if you need to. Many merchants allow contact and address changes for three hours but additions for only one, because an addition physically changes what has to be picked.

Use Shopify's Bogus Gateway, or place a small real order and refund it afterwards. Either works. What matters is that the order is created the same way a customer would create it, so the Order Status page you see is the one they will see.

Open the confirmation email, follow the link to the Order Status page, and check that the SelfServe block appears where you placed it and that the countdown is showing the window you configured. Then make a change: edit the address to something deliberately wrong, such as a real street with a postal code from another city, and confirm the validator refuses it and explains why. Then correct it and confirm it saves.

Go back to your Shopify admin and open the order. The new address should already be there, and the timeline should show the change with the previous value alongside it. If both are true, the loop is working end to end.

Finally, test the closed state. Create a fulfilment on the test order and reload the Order Status page. The edit controls should be gone and replaced by your support message.

Under Settings, then Status, switch SelfServe from Test to Live. The block becomes active for every order created from that moment. Orders placed before the switch are not retroactively editable.

Over the first week, open the change log and look at two things. First, how many edits are landing close to the end of the window, which suggests the window could usefully be longer. Second, how many customers are hitting the expired state and clicking through to support, which is the volume you have not captured yet.

Adjust the window once, on the strength of that week, rather than guessing again. Most merchants who start at one hour move to three; few who start at three move back down.