Computerized Accounting System (CAS) and Books of Accounts

Last updated: 2026-07-09 Summary:

• Every BIR-registered business keeps Books of Accounts; a Computerized Accounting System (CAS) is the software equivalent of keeping them by hand.
• Using accounting software to produce your official books generally means registering that system with the BIR.
• eKapital is built to be both — it generates the six prescribed books and the documents you submit to register it as your CAS.

Books of Accounts

Your Books of Accounts are the official accounting records the BIR requires you to keep and to be able to present on examination. They can be kept three ways: manual (bound paper books), loose-leaf (printed and bound periodically), or computerized (produced by a registered CAS). Whichever you use, the books are the record an examiner opens, and they must reconcile to the returns you filed.

In the Philippine set, this means the six prescribed books: the General Journal, General Ledger, Cash Receipts Journal, Cash Disbursements Journal, Sales Journal, and Purchase Journal. eKapital generates all six from your posted transactions — see Recordkeeping and audit for how they are produced and exported.

What a CAS is

A Computerized Accounting System (CAS) is accounting software used to keep your books electronically. Because the software is now producing your official records, the BIR expects the system itself to be registered — so that the agency knows what software is generating the books, what controls it has, and that it can produce a complete audit trail on demand.

Registration is handled through the BIR’s Compliance Document Requirements (CDR) process: you submit a package describing the system and providing samples, and your Revenue District Office (RDO) issues an Acknowledgment Certificate (AC). Under the Ease of Paying Taxes reforms, the AC number is what software-printed invoices display — it takes the place of the older Authority to Print (ATP) reference.

The exact documents, thresholds, and turnaround are set by BIR issuances and can change. Confirm the current CAS registration requirements for your business with your CPA or your RDO — this page describes the workflow eKapital supports, not the regulation itself.

How eKapital serves as your books and CAS

eKapital is designed to be your computerized books and the CAS you register:

• The books. It produces the six prescribed books directly from posted transactions, each carrying the required software header (system name, version, and generation timestamp).
• The audit trail. It keeps an exportable audit trail of what changed, by whom, and when, plus gap-free sequential numbering for issued invoices and receipts — both of which the BIR expects from a CAS.
• The registration package. It generates the CDR documents you submit to register the system — a system description, a process narrative, sample reports, a reports catalog, the Standard Audit File (SAF), and the standard annexes — and it tracks your registration status and Acknowledgment Certificate. See Prepare your CAS registration package.

Because your books, your audit trail, and your registration documents all come from the same system, the story you tell the BIR about your accounting system matches the records that system actually produces.

See also

• Recordkeeping and audit
• Prepare your CAS registration package
• BIR compliance overview