What happens if your broker makes a mistake? If you download regularly, you can spot errors quickly and notify your brokerage of any erroneous transactions.
Correcting mistakes in downloaded transactions
If your brokerage makes a correction to its records, you'll need to make the same correction to any erroneous transaction that you've already downloaded and accepted into your investment transaction list.
Downloading corrections
Quicken allows your broker to download any necessary corrections by simply recording a reversal transaction. A reversal transaction is basically an equal but opposite transaction to the one that contains an error. For example, if your brokerage erroneously recorded a transaction to buy 10 shares of stock XYZ at $20 per share, it might correct this error by recording a Sell transaction of 10 shares of stock XYZ, also at $20 per share. Your holdings are corrected, and your cost basis and capital gains remain unchanged.