Being Charged to Download Apps

You may need to have a payment method on file, even if the app you want to download is free.

If you can't make purchases or update apps, including free apps, you need to update your payment method or add a new one. 

See also -> Payment methods you can use with your Apple ID

Payment methods you can use with your Apple ID – Apple Support (UK)

You can also use your Apple ID balance as payment method: Add money to your Apple ID balance

Add money to your Apple ID balance – Apple Support (UK)