The article you linked is exactly what I followed to copy the company.  I also spent many hours on the phone with customer service reps during the backup process which took over 24 hours.  The article does not mention anything about invoices not staying linked to the estimates after transfer to new company. I have since discovered that the billable expenses are not linked to invoices as well.  Frankly, this new company file is useless to me if the project history does not copy.  I cannot bill against the estimate without knowing what has already been billed.  It just doesn't work.  

I upgraded to QBO Advanced in order to access the backup>copy feature, and it was my understanding that I would also receive a higher level of support.  Today I spent two hours on the phone most of which was waiting on a "next level" support person to advise.  I still don't have an answer.  Can you please provide a phone number which I can call to expedite this issue?  Every time I call, I have to explain my situation from the beginning regardless if the previous rep took notes or not.  I would greatly appreciate some guidance so I can get back to actually running my business.