Loyalty card in Apple Wallet and Google Wallet: how it works

01What a loyalty card in Wallet is

It is the digital version of the classic stamp card. Instead of paper, the customer saves a pass in the wallet app on their phone: Apple Wallet on iPhone and Google Wallet on Android.

Apple defines store cards as passes for discount, gift and loyalty cards from shops, which can show points, reward balances and conditions. Google offers its own loyalty card format, which is saved in the Google Wallet app.

The advantage for the customer is that they do not install yet another app, and the card does not get lost in a drawer. For you, the advantage is being able to keep the card up to date without printing anything.

02How the customer adds it

The procedure is simple for the customer, although behind the scenes it differs on each platform.

1. 1

   They scan a QR code at the counter or tap a link you send them by web, email or SMS.

2. 2

   They tap “Add to Apple Wallet” or “Add to Google Wallet”, depending on their phone.

3. 3

   The card is saved and they can show it at the till.

With Apple, passes can be installed from Mail and Safari on iOS, or from an app using the PassKit framework; Apple notes that passes should remain useful even if the user does not have your app. With Google, the pass is created through the Google Wallet API and delivered with an “Add to Google Wallet” link that works anywhere links work: web, email or SMS.

03What lies behind it: what the business (or whoever builds it) prepares

A card of this kind is not just a nice design. It needs technical set-up that each platform requires:

• Apple: a pass type identifier and a signing certificate created in an Apple developer account. The pass is a signed package containing its description in JSON, images and, optionally, locations. If the identifier does not match the certificate, the pass does not work.
• Google: a Google Wallet API issuer account and an authorised service account in the Google Wallet console, used to sign the link for each pass.
• A server of your own that generates the passes, stores each customer’s status and updates them when something changes.

This is the work we do in the digital loyalty card service: design, registration on both platforms and support.

04How stamps are updated

When the customer earns a stamp, the pass on their phone has to change. The mechanism is different in each system:

• Apple Wallet: the pass includes the address of a web service. When it is added, the phone registers with your server. When something changes, the server sends a silent notification through the Apple Push Notification service; the phone asks which passes have changed and downloads the new version, which replaces the old one.
• Google Wallet: you update the pass object through the API and the change is reflected in the saved card.

Apple reminds us that updates are not guaranteed: the user may be offline or may have switched off updates for the pass. Nor is it wise to trust what the screen shows for important decisions.

05Notifications: what can and cannot be done

There is more nuance here than is usually told. Neither the business nor whoever builds the card fully controls when a notification is shown.

On Google, if you exceed the limit, the notification request returns a quota error; you can still update the pass with messages that do not notify. Google may also limit notifications if it considers that you are bothering the user, and the customer must have notifications switched on. For location, the user must have granted precise, always-on access to location.

06How it is validated at the till, and why it matters

The card normally includes a code (QR or barcode) that is scanned. Apple recommends checking a unique identifier against your server rather than trusting the data in the pass itself, and not tying a single-use pass to a single device, because passes sync with iCloud and the user can forward them.

In other words: the stamp must not “exist” only on the customer’s screen. The system must record on your server when a stamp is added and when a reward is redeemed, to avoid duplicates and errors.

07What to expect (and what not)

• It is a tool to make it easier for customers to come back, not a guarantee of loyalty.
• It works well with customers who already use Wallet; not all of them will do so straight away.
• It needs maintenance: certificates, keys and accounts that expire or change.
• Customer data you collect is subject to the GDPR; explain it in your privacy policy.

Before launching it, define what you are rewarding, how many stamps are needed and how a reward is redeemed. If you also want to attract new customers, the guide How to rank a website on Google is a good complement.