I completely understand the idea behind this, but cannot understand how to make this happen.

• What does “linked transactions” mean? Both sides? (<-- of what)
  
  
• How do we know which “sales transaction” to try and change? The sub-client has many (years even) of transactions.
  
  • What customer’s name should be used? The only available name for that transaction is the sub-client’s name? It is already the sub-client’s name, as it should be. However, QBO shows it as “Parent | Sub-Client” – There is no Sub-Client by itself to select from in the list.
  
  
• I’ve tried to do this, from what I can guess, but it didn’t make any difference. I still received the same error message. I changed all the November payments and invoices from the sub-client to a dummy account. Then tried to change the sub-client to bill with client, instead of parent, and still had the error which wouldn’t allow me to change the bill with option.