If any wallets, exchanges, or transactions are excluded from your ZenLedger transaction record, your IRS tax filing will be incomplete.
An incomplete tax return can potentially expose you to IRS penalties for providing incomplete information and/or for underpayment of taxes due.
On the other hand, missing information could incorrectly overstate capital gains or understate capital losses resulting in a higher tax bill.
The eventual outcome is that a materially incorrect tax return can cost you both time, money, and energy.
For more information, read: Do I need to upload all my transactions?