my kids can't download apps. It says there is a billing problem

If a message says 'billing problem with previous purchase' or 'verification required', try the things in this article -->

If a message says 'billing problem with previous purchase' or 'verification required' - Apple Support

You get a billing problem message because there is a problem paying for something a person bought in the past and this needs to be resolved before Apple will let you make a new purchase, even free items. It isn't a problem with a specific item, it's with the payment method used by you or—in the case of Family Sharing—the Family Organizer.

Get the payment method owner to review their payment methods as in this document: 'Add a payment method to your Apple ID' on an Apple mobile device, a Mac, or a PC; click here --> Add a payment method to your Apple ID - Apple Support

- Payment methods with a problem will appear in red. This document tells you how to remove problem payment methods --> Remove a payment method from your Apple ID - Apple Support

- If the person is updating an old card and has ongoing subscriptions the person may need to first add the new card and make it the primary payment method before deleting the old card.

Related documents:

If the payment method is declined in the App Store or iTunes Store, click here --> If your payment method is declined in the App Store or iTunes Store - Apple Support

"There is a billing problem with a previous purchase." = "you have an unpaid balance in the App Store or iTunes Store"

- 'If you can't remove your last payment method or use no payment method with your Apple ID' click here --> Remove a payment method from your Apple ID - Apple Support

If none of the self-help solutions resolve your situation then ask Apple for help. Click here --> Choose your country or region - Official Apple Support Select your country, then a product. If you don't see one that handles your issue then keep experimenting with selections until you reach one that gets you a chat session or a telephone call and get the representative to redirect you.

or:

Contact Apple for support and service --> "See a list of Apple phone numbers around the world." - Contact Apple for support and service - Apple Support

You ask one question but then switch track...

See this article about updating payment methods on various platforms (iPhone, Mac, etc.): If you need to change or update your Apple ID payment method - Apple Support

"If you change your address, the credit or debit card information that you use with your Apple ID might be automatically updated by your financial institution, and you don't need to take action. But if there's an issue [such as you having a subscription or being a Family Sharing Organizer], add a new card first, then remove the old card."

Here is how you update your payment method on an iPhone or iPad:

1. Open the Settings app.

2. Tap your name.

3. Tap Payment & Shipping. You might be asked to sign in with your Apple ID.

4. Tap Add Payment Method, enter the new payment method, then tap Done.

5. Tap Edit.

6. Tap the red delete button next to the old payment method, then tap Delete.

Billing information problems

I can’t download apps not a family account

Yes