Editing a subscription changes what it bills going forward. It can't move money that's already been invoiced, and it can't change who pays or when.
A subscription has two different people attached to it: whoever is billed for it (the payer), and whoever each product row is for (the recipient — usually the player using the product). The payer is fixed for good once the subscription exists. The recipient can change, but not from the Edit screen.
Edit a subscription
Go to Payments > Subscriptions and open the subscription.
Click Actions > Edit.
Fixed forever. The billing date and the payer are set when the subscription is created and can't be changed here or anywhere else. If either needs to be different, cancel this subscription and create a new one with the right values.
You can change:
Products and prices — add or remove products, change quantities, or switch to a different price for the same product. You can't add a one-off product to a subscription, or mix in a product on a different billing cycle (e.g. a yearly product on a monthly subscription).
Discount — apply or remove a discount code.
Installment count — installment plans only. The remaining balance is recalculated across the new count starting with the next invoice.
Days until due — under Advanced options, shown when the subscription is set to manual collection. How long an invoice stays open before it's marked past due (1–365 days).
Auto-charge customer — toggle whether new invoices are charged automatically or sent for manual payment.
Changes apply from the next invoice the subscription generates. Invoices already issued aren't touched — handle those separately with Void an invoice or Refund a payment.
Change who a product is for
To move a product to a different person — say, a subscription was set up under the wrong sibling — use Actions > Change product recipient on the subscription. This is a separate action from Edit, and it only works when every product row on the subscription currently belongs to the same person; a subscription already split across several people can't be reassigned this way.
Open the subscription and click Actions > Change product recipient.
Pick the new recipient, click Confirm, then confirm again in the dialog.
Unlike an edit, this rewrites every order the subscription has already generated, not just the next one. It only changes who the product is for — the payer stays the same.