Sub-account Move to a New Master

When I move one of my sub-accounts from Master Account A to Master Account B:

  1. Is it possible to keep the same sub-account number in the new master? If yes, do I need to make any changes to my AWS integration (like unlink and link or creating new IAM user).
  2. Is it possible to get a new sub-account number in the new master? If yes, do I need to make any changes to my AWS integration (like unlink and link or creating new IAM user).