1. The signup screen
Some apps ask “Have a code?” while you create an account. Enter it before submitting registration. If the account already exists, adding the code later may not count. Take care with similar fields for promotions, gift cards and partner IDs.
2. The basket or checkout
Shopping and subscription brands may put the box next to the price breakdown. Apply the code, wait for the total to recalculate, and inspect any later renewal amount. Butternut Box’s help pages say its new-customer referral can be entered during signup before the final checkout.
3. The invitation link
Many programmes do not need you to type anything: the unique link carries the referral identifier. Do not remove the link’s query string or switch to the provider’s ordinary homepage. If the offer does not display, stop and check the provider’s support guidance before paying.
4. An account’s referral area
The “Refer a friend” section is usually where an existing customer gets a link to share, not where a new customer claims one. For instance, the general giffgaff programme page describes the benefits, while a member must sign in to copy their personal invitation. Never guess a code based on someone’s name.