The resolution, based upon Apple Support, is very obscure. To correct the billing address the had me do the following on my iPad:
1) SETTING
2) APPLE ID
3) MEDIA & PURCHASES
4) VIEW ACCOUNT
5) MANAGE PAYMENTS
6) Add a new credit card more as a ‘position holder’ (You will note you are required to add your ‘address’.).
7) Delete the card causing issues.
8) Re-add the old card just as you would IF you’d never used the card before. Again, you will note the system requires your billing/shipping address.
9) You can delete the ‘position holder’ if you so desire.
10) EXIT back out as you normally would.
It took us a while to locate the old address. But, I’m pretty certain I’ll no longer have any sales tax issues.
Don’t know why they hid it, but there must have been some ‘logical’ reason.