difference between wallet(bitcoin core) total and blockchain final balance

[plundertasche]

Hello,

my bitcoin core is in sync and has only about 15 transactions in the last 3 years.

The "Total Balance" in bitcoin core client (v.0.12.1 64bit) differs from the final balance amount at blockchain.org
Additionally at "https://www.walletexplorer.com/" the bitcoins and some transactions (with more than 100.000 confirmations in bitcoin core) are missing.
It looks like at least three transactions are not in alignment. Strange and expensive mismatch, isn't it?

How can this happen or where is my misunderstanding for this?

best regards and many thanks for enlightening

plunder

[achow101]

The "problem" (really just a misunderstanding) is due to change addresses. When you spend some Bitcoin, change is created, similar to cash. Bitcoin Core automatically generates a new change address for every transaction that has change and the change goes to that address. However, it doesn't tell you about that address since it isn't particularly necessary for you to know it. Sites like walletexplorer do not know that the change address is in your wallet unless it is spend linked, which in this case it probably is not. Those sites do not actually know the addresses in your wallet, it can only guess based upon what it sees in the blockchain.