You can only sell coins and currencies you own.
If the tax report detects sales without a suitable purchase, it will display a warning.
In this case, a purchase of 0 USD (or whatever your FIAT currency is) will be assumed, which increases your gain and therefore also the tax.
Please make sure that all your purchased coins and currencies are correctly and completely listed in CoinTracking.
Look at the detailed calculation in the "Overview of all created Tax Reports table" to see all sales with a warning.
Please note that deposits and withdrawals do not have a cost basis, as they are considered movements between wallets or exchanges.
That's why they will not be calculated in the tax report.
If you have bought coins, you need to add them into CoinTracking as Trade instead of a deposit.
The exception where transfers might trigger a warning in the tax report is when using Depot / Lot separation. In this case, the cost basis is generated by the withdrawal and transferred to the new account with the deposit. If the deposit occurs before the withdrawal, the cost basis cannot be transferred, which results in a warning.
In such cases, the solution is to correct the timestamps to ensure the order of withdrawal and deposit is accurate. You can find the warnings related to depot separation transfers in the tax report settings:
