I’ve been experimenting with the API this morning, but I can’t figure out what’s going on with the account_balance attribute. Put simply if you add up the amount on each transaction, it doesn’t always agree with the account_balance on that transaction. At the end of all my transactions, I’m approximately £3 out.
We’ve seen issues with TFL transactions in the past which may be the cause?
Obviously the Customer Support team have access to much more information about your transactions so if you want the conclusive answer, I’d recommend asking them to look into this.