BIR CAS registration done properly, the first time
We prepare the system description, functional flowcharts and sample output reports your Revenue District Office requires, and stand with you through the system demonstration.
What BIR CAS registration is
A Computerized Accounting System is any software you use to keep your books of account electronically. Under Philippine rules, that system must be registered with the Bureau of Internal Revenue before you rely on it for statutory records. Registration is the BIR's approval of the system itself — not of a particular transaction, and not the same thing as EIS e-invoicing compliance.
The output of a successful application is an Acknowledgement Certificate or Permit to Use, which specifies the system modules and version covered. Material changes to the covered system require an amended filing.
Registration requirements and processing practice vary by Revenue District Office and are periodically revised by Revenue Memorandum Circular. We confirm current requirements with your specific RDO before preparing the pack — we do not work from a template that was accurate two years ago.
Who needs it
- Businesses whose gross annual sales exceed the BIR thresholds requiring computerised books
- Businesses required to issue computer-generated invoices and receipts
- Any business voluntarily adopting a computerised accounting system in place of manual books
- Businesses moving from a loose-leaf or manual arrangement to an ERP such as Dynamics 365 Business Central
There is a second reason CAS registration matters right now: taxpayers already using a registered CAS, computerised books of accounts, or e-invoicing software fall inside the first BIR EIS compliance group, with a 31 December 2026 deadline. Registering a CAS and planning EIS readiness are therefore best treated as one project.
What the application pack contains
| Deliverable | What it demonstrates |
|---|---|
| Completed BIR CAS application form | Entity details, RDO, system identification and the modules being registered. |
| System description | Narrative of how the system captures, processes, posts and stores accounting entries, including security and access controls. |
| Functional flowcharts | Process diagrams for each covered cycle — procure to pay, order to cash, record to report, fixed assets — showing where entries originate and how they reach the ledger. |
| Sample output reports | Printed specimens of books of account, journals, ledgers, invoices and receipts the system produces. |
| Supporting documentation | Certificate of Registration, prior permits where applicable, and the system's audit-trail evidence. |
The registration process
- Pre-evaluation. The documentation pack is submitted to your Revenue District Office for initial review.
- System demonstration. A live walkthrough for the RDO evaluators — transactions entered, posted, and traced through to the statutory reports.
- Approval. The BIR issues the Acknowledgement Certificate or Permit to Use covering the demonstrated modules and version.
- Amendments. Material changes to the registered system are filed as amendments so the permit continues to reflect what you actually run.
Where applications typically fail
- Flowcharts that describe the software, not the business. Evaluators want to see your approval points and segregation of duties, not a generic vendor diagram.
- Sample outputs that do not reconcile. If the specimen journal does not tie to the specimen ledger, the pack goes back.
- No demonstrable audit trail. The system must show that posted entries cannot be silently altered, and that every change is attributable.
- Reports requiring manual assembly. Statutory reports should be reconcilable to the general ledger without spreadsheet intervention.
How we handle it
CAS registration support is included in the scope of our Business Central implementations and available as a standalone engagement for businesses running another system. We prepare the full pack, rehearse the demonstration with your finance team, and attend the RDO session with you.
Because Business Central produces the audit trail, immutable posting and reconcilable reporting the BIR expects, the registration work is documentation and demonstration rather than remediation — which is where most of the delay in a CAS application actually comes from.
Frequently asked questions
Is BIR CAS registration the same as EIS e-invoicing compliance?
How long does CAS registration take?
Do we need to re-register if we change our system?
Can you handle CAS registration if we do not use Business Central?
What happens if we operate an unregistered computerised system?
Planning a CAS registration?
We will confirm current requirements with your RDO, prepare the pack, and rehearse the demonstration with your finance team before the session.