What is a Sell Without Buy Error?
SWB errors on the Transactions page indicate that some outgoing transactions (e.g. sell, trade, transfer) are missing basis from an incoming transaction (e.g. investment, gift, income). In the drop-down menu at the top, click the arrow next to Select Category, and choose Sell Without Buy to review your Sell Without Buy transactions.
Why does it matter?
To produce accurate tax reports, it's essential to provide ALL transactions since your very first crypto coin and to pair them (especially self-transfers) appropriately.
Missing basis on a cryptocurrency transaction or mismatched sides of a self-transfer could drastically change tax outcome, and it will result in materially incorrect tax reports.
For more on this, read Do I Need To Upload All Transactions?
How do I fix Sell Without Buy errors?
SWB errors can have many causes, so it's important to explore each relevant potential solution until all of the errors are cleared.
Here are a few places to begin investigating:
Duplicate Outgoing Transactions:
In this case, all of the incoming transactions are correctly paired with outgoing transactions, but each outgoing transaction is entered twice, leaving half of them without a match.
The system does not import duplicates when it can identify them, but details like the timestamp might be different by a few seconds, one value might have fewer decimal places, or the duplicate transactions might come from two different sources (CSV upload also imported by API).
Search by Token or Address on the Transactions page.
Skim through for lines that look like they may contain duplicate information.
Edit the transaction to either delete or (ideally) ignore the second copy.
Sometimes an exchange (like Bittrex) requires multiple uploads to provide a complete picture.
Check the detailed table at the bottom of the Transaction Sources page.
Confirm that each exchange or wallet has at least 1 non-zero number in the Deposit column.
If the deposit column values are ALL 0, refresh the API connection, re-sync the wallet, and check the CSV files that you imported.
Answer these questions before contacting support:
Do you have 100% of wallets and exchanges uploaded? Have you checked to make sure you can find the actual transactions you expect to see and verify that they are in but not matching up?
Check datestamps - this is the #2 cause of things not matching up after not having all sources uploaded, the "receive" should be at least a second or two after the "send".
If you have already put in manual self-transfers, duplicates might have occurred. Please make sure not to put any manual self-transfers in until you have imported all sources and checked datestamps!
Other potential causes:
Manual transaction is not assigned to Exchange so system cannot pair them.
Inaccurate transaction type selected (incoming vs incoming self-transfer): http://support.zenledger.io/en/articles/2846585-mark-self-transfers
Missing an Exchange or Wallet completely.
Finally, check the GUA - could be a few decimal places not accounted for.