The documents are entered into accounting software of your choice (Xero, Quickbooks, MYOB, Saasu, Wave apps, etc.)or any such accounting platform.
We then store the scanned copy of the source document along with the transaction to make it easily accessible in accounting software or on related add-ons.
All the entries would be cross-checked and reviewed with the source documents (i.e. Purchase Invoice/Scanned Bills etc against the Purchase/Expense transaction, respectively).
Benefit: This will leave an audit trail for every transaction for future use.