Ask whose record
An account balance is a statement about a particular record and relationship. It is not a universal description of all money connected to a customer. Bank deposits, internal product balances and unsettled payment records may describe different claims or states and must be labelled accordingly.
Available is a calculation
A product may calculate available value from a recorded balance together with holds, restrictions and pending movements. Document that calculation. Otherwise support, engineering and finance can all display different numbers while each believes its own screen represents the single authoritative customer balance.
A hold example
In a fictional wallet, the recorded balance is €100 and €30 is reserved for an outstanding operation. Under the product’s stated rules, available value is €70. Releasing the reservation restores availability without necessarily creating a new incoming payment or changing the underlying recorded balance.
Keep the history
Preserve an auditable movement history with stable references and explicit corrections rather than silently replacing balances. Reconcile internal totals with the relevant external accounts. A tidy interface should still let authorised investigators explain which movements and restrictions produced the amount shown to the customer at a particular time.