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Quickbooks Error Code: (6140)


  • Quickbooks Error Code (6140): Duplicate Document Number Error 


  • Clio Manage
  • Quickbooks

Additional Information: 

  • For a full list of Quickbooks Error Codes click here.
  • To find Quickbooks errors click here.


This error occurs when Clio attempts to sync something to QBO, but that number has already been used elsewhere in Quickbooks Online. This could be a bill, bill payment, interest charge, credit note, or something else. There are cases where a duplicate number may not appear to exist in Quickbooks, but the invoice number is still not accepted by Quickbooks. 

Numbers in Quickbooks must be unique. For instance, a Bill in Clio may not sync to QBO because a credit memo in Quickbooks already uses the same number.


The error shown in Clio will give you clues as to what record in Quickbooks is conflicting with Clio. For example:

Code (6140): Duplicate Document Number Error : You must specify a different number. This number has already been used. DocNumber=1234 is assigned to TxnType=Credit Memo with TxnId=111

  • DocNumber is the document number being used by Clio that already exists in Quickbooks and causing the error. 
  • TxnType is the type of record or transaction in Quickbooks that has the duplicate Document Number Clio is trying to use.
  • TxnId is an ID used by Quickbooks to identify the record and can be found in the URL of the record in Quickbooks.


This can be used to pull up the offending record in Quickbooks. In the example above:

  • The Credit Memo with the TxnId 111 can be found at:
  • An invoice with with the TxnID 123 can be found at:

For different TxnTypes, open a transaction of the same type in Quickbooks and change the txnId in the URL.



Retry the sync

  1. Select Settings
  2. Select Bill Syncing 
  3. Locate the Error Code by scrolling down 
  4. Select Retry



If bills in Clio are causing the 6140 error, either:

  1. Add a Bill Prefix in Quickbooks Sync Settings (see here) and retry the sync (see above)
  2. Edit the bill's number in Clio (see here) and retry the sync (see above)
  3. Edit the invoices number in QBO (see here) and retry the sync in Clio (see above)


Credit Memos

To change the Credit Memo No in QBO follow the steps below:

  1. Search for the document number in the Global Search
  2. Select the Credit Memo from the search results
  3. Change the number in the Credit Memo no. field
  4. Click Save and Close or Save and Send
  5. Click the Retry button in Clio (see above)

Finally, if the above steps still do not resolve the issue, try deleting the invoice and re-generating. 


Trust Transactions

See here. 




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