I have never seen anybody ever report not being able to update an address because of an outstanding balance. Are you sure that is the reason? Read this article about managing the information you use with your account --> Manage and use your Apple Account - Apple Support
Whatever the reason, if you owe Apple money they will insist that you pay what you owe or they may block you from doing additional purchase downloads or something requiring financial solvency. I suspect that is the reason for that message. Read the links below about various ways to pay for items in the iTunes and App Stores.
- Add a payment method to your account. See this article about payment methods that you can use with your Apple Account --> Payment methods that you can use with your Apple Account - Apple Support then see this article about how to add a payment method to your Apple Account --> Add a payment method to your Apple Account - Apple Support
- Add money to your Apple Account balance - "Use a payment method, such as a credit or debit card, to add funds to your Apple Account balance." This takes the previous payment method one step farther by optionally using it to irreversibly add funds to an Apple ID account balance instead of having the card charged each time.
Click here --> Add money to your Apple Account balance - Apple Support
If no option is shown to "Add Money to Account" using this method (you only see using gift cards) then it may not be available in your country. Use a gift card instead.
- This article outlines how to redeem an Apple Gift Card or App Store & iTunes gift card --> Redeem your Apple Gift Card, App Store Card, or App Store & iTunes Gift Card - Apple Support
- You could also look into joining a Family Sharing group where the family Organizer's payment method is used. To learn how to join a Family Sharing group, read the section "Join a family group" in this support article --> How to set up Family Sharing on your iPhone, iPad, or Mac - Apple Support
Typically a reason to have to zero balance is because you wish to do a country change. There are two ways you can try:
#1. If you still have a valid credit or debit card from your original country, purchase an item for slightly more than your balance. The remainder will be billed to your card, leaving you with nothing in your account balance. This is the only solution for you to empty your balance if cannot contact Apple Support. This method is the easiest and has the additional benefit that you get to use your money for something for yourself instead of simply giving it to Apple.
#2. Ask Apple Support to remove and keep the balance. Live support is not available in all countries.
- Click on the special chat contact link at the bottom of this support article ➔ Check your Apple Account balance - Apple Support
- Link to chat with Apple Accounts support ➔ https://getsupport.apple.com/?caller=kbase&PGF=PGF63005&category_id=SC0998&symptom_id=20198
- General Apple support and service contact ➔ Contact Apple Support - Apple Support If live support options are available they will show near the bottom left. Telephone numbers may only work when calling from the same country. If numbers show as colored links, click on them for more options.
- With an iPhone, iPad, or Vision, you may be able to chat using the Apple Support App if it is available in your country ➔ https://apps.apple.com/app/apple-support/id1130498044
If you can neither add a payment method nor contact Apple, your alternative is to create a new Apple Account when you are in the new country. Avoid doing that if at all possible. It may cause many complications with your current account content.
When changing account regions there’s a full set of guidelines in this support article ➔
Change your Apple Account country or region - Apple Support