How do I update my payment information online?

Android

On your Android phone or tablet, open the Google Play app. At the top right, tap your Profile Icon. Tap Payments & subscriptions > Payment methods > More payment settings. If asked, sign in to Google Pay. Then under the payment method you want to remove, tap edit, from there make your changes. Tap update and your changes will be saved.

For more information please visit Google Support. 

Apple

On your Apple device, open the Settings app and tap your name. Tap Payment & Shipping. You might be asked to sign in with your Apple ID. If you need to update the billing information of an existing card, tap the payment method, then tap Edit.

For more information please visit the Apple App Store.