For auto-synced wallets, Koinly carries out a comparison of your balances on Koinly against the balances on your exchange.
Koinly will display two balances, a Calculated Balance and a Reported Balance:
Reported balance - the amount that the API says you have in your wallet
Calculated balance - the amount Koinly has worked out you have in your wallet.
If the Reported Balance is correct but the Calculated Balance is wrong, then something is missing from your imported data - see Some transactions are missing
If your Calculated Balance is correct but the Reported Balance is wrong, you can choose to Ignore reported balances in the wallet settings.
Why does the balance on Koinly not match my actual balance?
The balances on Koinly are calculated using the imported transactions so unless some transactions are missing on Koinly the balance should always match what you have on your exchange. This is a good way to determine whether or not all your transactions have been imported correctly.
If an issue is found you will notice a yellow warning next to the wallet as seen below (only for auto-synced wallets):
Clicking on the warning icon will show the difference between Koinly's balance and the balance reported by the exchange:
Difference = Koinly Balance - API Balance
If the difference is positive, it means the balance on Koinly is higher than your actual balance. This could mean that a withdrawal or a sell of that coin is missing.
A negative balance means the opposite. Perhaps a deposit or a purchase is missing.
If the differences are quite small ex. 0.001 then you can usually ignore them as they are caused by rounding precision. Larger differences may require more attention though.
Reasons for balance mismatches
Koinly calculates the balance for each of your coins from the transactions that you have in that wallet. This means that if a transaction is missing then the balance on Koinly will not match what you actually have on the exchange/wallet.
This can happen for a number of reasons:
Numerical Rounding - If you see small differences like 0.00000001 then you can safely ignore these as they are the result of rounding precision.
Airdrops - Some exchanges (ex. Kucoin) do not report your airdrops via the API or in CSV files, so Koinly has no way of knowing about them. If you go on to sell the airdropped coins, you will get a Negative balance error because you have no balance in that coin.
Open Orders - Koinly ignores open orders/trades until they are closed so you might see differences if your open order has been partially fulfilled. In such cases just wait until the order closes and the balances should match again.
Missing transactions - If the differences between the balances is big then it means some transactions have not been imported. This is quite common and can usually be resolved by following the instructions for the wallet that you are adding. For example, Binance does not return trades for delisted coins via their API so you have to import these trades using CSV files instead.
Sometimes the only way to figure out the issue with Missing transactions is to compare the imported transactions on Koinly one-by-one with the transactions on your exchange account. This may seem like a long process but Koinly has some tools built exactly for this job.
The balance on Koinly is the same as my exchange but this warning is still there...
This warning is only updated after a sync has been completed, so it will disappear the next time the wallet is synced (in most cases). Note that for Ethereum wallets you may continue to see this warning even after a re-sync, this usually happens for coins that have undergone a token/address swap. Just make sure your balance on Koinly is correct and ignore the warning if it is.