QB files can't be older than 2007 edition
Quickbooks files for conversion must be in 
  1. .qbb
  2. .qbw
  3. .qbxml

Accountant's verions or MAC files will need to be converted to one of the above formats

  1. IMPORTANT: Make sure Quickbooks for conversion to Xero is  equal to or less than 1 GIGABYTE or If Quickbooks online? it needs to be exported as qbxml file.
  2. Confirm multi-currency in Quickbooks has not been activated.
  3. Quickbooks Chart of Accounts must have fewer than 700 accounts.
  4. Quickbooks Chart of Accounts must NOT have duplicates nor the same number. (Before you uplaod your Quickbooks file, make sure you have assigned numbers in your chart of accounts)
  5. Delete inactive accounts
  6. Turn on account numbers in QB
  7. If turned on each QB account has a UNIQUE number/ID.
  8. If using any online services, make sure all accounts have posted and disconnect any online services
  9. Go to Xero 'home page if you dont have login and start a free trial if you dont have Xero account.
  10. Go to My Xero and add your organization if you haven't done so already.
  11. Important: Make sure you click on the link: " Convert your Quickbook file for free" <-- I failed to click on it and later found out that once you are at the point of no return that you will need to recreate a new organization all over again and click on conversion option.
  12. Enter name of organization and check box to convert my Quickbooks file and click continue
  13. Browse computer to select Quickbooks file you have prepared.
  14. Check the box if your Quickbooks file has a password: and enter your Ad