BIR Computerized Accounting System (CAS) and Computerized Books of Accounts (CBA): The Complete 2026 Guide to Registration, E-Invoicing and Annual Compliance

Most growing Philippine businesses outgrow handwritten journals quickly. Once you run your books in accounting software, the Bureau of Internal Revenue (BIR) expects you to register that system before you rely on it for your books, and in many cases before you print a single system-generated invoice.

This guide is for owners, finance managers and bookkeepers who are moving to, or already using, a computerized accounting system (CAS) or computerized books of accounts (CBA). It covers who needs one, how CAS compares with manual and loose-leaf books, the current registration process (the old Permit to Use is gone for new applicants), the documents you'll prepare, realistic timelines and costs, and the yearly obligations that follow.

It also explains how CAS fits with the BIR's e-invoicing deadline of December 31, 2026 and the new creditable withholding tax (CWT) field on invoices. Figures and rules are as of October 2026.

Key takeaways

• No more Permit to Use for new systems. Since Revenue Memorandum Circular (RMC) No. 5-2021 and Revenue Memorandum Order (RMO) No. 9-2021, you register your CAS or CBA and the BIR issues an Acknowledgement Certificate (AC). Permits to Use (PTU) issued earlier stay valid unless revoked or the system has a major enhancement.
• The AC is free and fast on paper. The BIR Citizen's Charter (2025 edition) lists no processing fee and a total processing time of about 3 days when you apply through the Online Registration and Update System (ORUS), and 2 days and 45 minutes at the Revenue District Office (RDO).
• Five core documents. You submit a sworn statement (or joint sworn statement with your software provider) with the Annex C-1 system description, sample invoices, sample books, a printed audit trail, and the signed Annex B functional and technical requirements.
• Large Taxpayers must use CAS. For everyone else it's optional. You choose between manual, loose-leaf or computerized books.
• Register your e-books every year. Computerized books must be registered through ORUS within 30 days after the close of each taxable year (January 30 for calendar-year taxpayers). For taxable year 2025, RMC No. 4-2026 extended that to February 17, 2026.
• An AC doesn't let you issue e-invoices. Under RMC No. 98-2026, CAS and CBA users with electronic invoicing are covered by mandatory e-invoicing by December 31, 2026, and need a separate Permit to Issue (PTI) Electronic Invoice plus an EIS Certification within six months.
• Keep electronic records for five years. The Ease of Paying Taxes (EOPT) Act set a five-year preservation period, and computerized books are preserved as electronic copies.

Overview

CAS, CBA and components: what the terms mean

RMO No. 9-2021 defines the systems you may need to register:

• Computerized Accounting System (CAS): a set of integrated components that handles the full accounting cycle, from the start of a transaction and the issuance of invoices up to financial reports. If any invoice is issued manually, the BIR treats the system as CBA instead.
• Computerized Books of Accounts (CBA): software that generates books of accounts only, such as the general journal, general ledger, sales journal, purchase journal and inventory book.
• Components: separate systems that produce accounting records, such as ordering, booking, billing, payroll, accounts receivable and payable, and sales receipting systems linked to your CAS or CBA.
• Electronic Storage System (ESS) and middleware: systems that store your records or move data between applications, including report writers.

The rules apply whether your software is off-the-shelf, customized, built in-house, or cloud-hosted. They also apply when a third-party provider runs it for you.

Who it's for

RMC No. 65-2025 also says registration of loose-leaf books or CBA can't be processed at the same time as the issuance of your Taxpayer Identification Number (TIN). Get your TIN first, then register the system.

Manual vs loose-leaf vs CAS/CBA

Read our companion guide to loose-leaf books of accounts if you're weighing that option instead.

How the BIR permits fit together

Timeline

Here is a realistic timeline for a business that registers a cloud CAS and then sets up e-invoicing.

The timeline assumes complete documents and a responsive software vendor. RDO workload, document deficiencies and vendor readiness for the BIR's e-invoicing format can stretch it. The EIS testing row is our estimate; RMC No. 98-2026 sets only the six-month outer limit.

Requirements

For the Acknowledgement Certificate (CAS, CBA or components)

The BIR Citizen's Charter (2025 edition) lists these requirements for both walk-in and ORUS applications:

• Sworn Statement (Annex C of RMO No. 9-2021), or a Joint Sworn Statement (Annex E) if a tax service provider or third-party software provider supplies or runs the system
• Summary of System Description, Commercial Invoices/Receipts/Document Description, Forms/Records and Reports Specification (Annex C-1), attached to the sworn statement
• Sample printouts of principal and supplementary invoices that will come from the system, showing the mandatory invoice information (as declared in Part V of Annex C-1)
• Sample printouts of the books of accounts and other reports the system generates, compliant with RR No. 9-2009 (as declared in Part VI of Annex C-1)
• A printed copy of the audit trail (the system's activity log)
• The signed Standard Functional and Technical Requirements (Annex B of RMO No. 9-2021)
• A certification from the purchasing company allowing you to use its system, only if the software license is under your parent or affiliate's name

For ORUS filing, upload each document as a JPEG, PNG or PDF file, with a maximum of 25 MB.

Joint sworn statement for cloud and outsourced systems. If a provider supplies or operates your system, RMO No. 9-2021 requires both of you to sign a joint sworn statement. It must state that the system has no facility to suppress sales or income. You must register before your contract with the provider takes effect, and notify your RDO before the contract ends, because termination automatically cancels the registration.

If you transact through a representative

• Individuals: a Special Power of Attorney (SPA) and a government-issued ID of both you and your representative
• Corporations and partnerships: a Board Resolution or Secretary's Certificate (a Written Resolution for a one person corporation) naming the representative, plus a government-issued ID of one signatory and the representative

For the annual registration of computerized books

The BIR's July 2025 Checklist of Documentary Requirements (CDR) and the Citizen's Charter list these for manual filing at the RDO:

• BIR Form No. 1905 (2 originals), for manual filing only
• A photocopy of your AC or PTU for CAS/CBA
• A transmittal letter listing each file's name, type and size, with the USB drive, DVD or other storage holding your e-books in Standard Audit File format, labeled with your name and the taxable year
• An affidavit attesting to the completeness, accuracy and appropriateness of your computerized books

Online filing through ORUS is the default. Under RMC No. 4-2026, manual filing is accepted only when the BIR has announced that ORUS is unavailable or you have a screenshot of the error.

Step-by-step procedure

Step 1: Confirm your TIN and pick the right category

Make sure your BIR registration (Form 2303) is complete and your ORUS account works. Then decide whether your setup is a CAS (the system issues your invoices) or a CBA (the system keeps your books but invoices are issued manually). This choice drives which samples you submit and whether e-invoicing applies to you. Where: ORUS at orus.bir.gov.ph. Time: one day.

Step 2: Configure the system before you document it

Set up your chart of accounts, books (general journal, general ledger, sales and purchase journals, and any subsidiary ledgers) and invoice templates. Invoices must carry the mandatory information under the invoicing rules of RR No. 7-2024, as amended by RR No. 6-2026, which now requires CWT to be shown as a separate item when it applies. Confirm the system keeps an audit trail. Time: 1 to 10 working days, depending on the vendor.

Step 3: Prepare the sworn statement and annexes

Complete Annex C (or the joint Annex E), Annex C-1 and Annex B from RMO No. 9-2021. List every book, report, principal invoice and supplementary document the system will produce, and every POS or CRM linked to it (brand, model, serial number, Machine Identification Number and PTU number). Print samples and the audit trail. Have the sworn statement notarized. Time: about 5 to 8 working days.

Step 4: File the application in ORUS or at your RDO

File with the RDO or Large Taxpayer office where your head office is registered. A branch that adopts a system ahead of the head office files with its own RDO, with a certification from the head office RDO. Affiliates, franchisees and sister companies each register separately, even if they share the same server and software. Where: ORUS (Secondary Registration) or the RDO Client Support Section. Form: no BIR Form 1900 is required for CAS since RMC No. 5-2021.

Step 5: Receive your Acknowledgement Certificate

The RDO issues the AC within three working days of complete documents, per RMO No. 9-2021. It carries an AC Control Number (ACCN) that must appear on your system-generated invoices. There is no system demonstration before approval, but the RDO may ask you to amend the sworn statement, and it will run a post-evaluation later. A discrepancy in your documents is grounds for a Notice of Denial. Fee: none.

Step 6: Apply for a PTI Electronic Invoice if you're covered

If your CAS or CBA issues electronic invoices, or you fall under another covered group in RMC No. 98-2026, file for a PTI Electronic Invoice at your RDO. The BIR evaluates it within 20 working days. Each distinct invoicing system needs its own PTI. See our guide to the December 31, 2026 e-invoicing deadline.

Step 7: Pass EIS Certification

Complete the online tests on the BIR's EIS Certification Portal (eis-cert.bir.gov.ph) within six months of your PTI. RMC No. 98-2026 says the process has five mandatory tests, or seven with an API callback. Missing the six-month window is a ground to revoke your PTI.

Step 8: Set up downtime invoices

If your system has no automatic failover, RMO No. 9-2021 lets you issue manual invoices during outages. They must be printed under an ATP, and you may keep no more than 1,000 sets at a time for this purpose. RMC No. 98-2026 adds that e-invoicing users must later replace each manual invoice with an e-invoice that references it.

Step 9: Register your e-books every year

Within 30 days after the close of each taxable year, export your books in SAF format and register them through ORUS. Print the QR stamp and keep it on file. Fee: none.

Estimated costs and budget

BIR registration of a CAS costs nothing in government fees. The ₱500 annual registration fee was also removed by the EOPT Act starting 2024. Your real costs are software, notarization and, if you choose, professional help.

Budget to prepare. Government fees for CAS are zero. Your fixed costs are notarization and, if you file manually, a storage device. Plan for software as a recurring monthly cost and check whether e-invoicing, multi-branch use and extra users cost more. Professional fees are optional but worth it if you have branches, a POS integration or a custom system. Prices are estimates as of October 2026, and US-dollar plans move with the exchange rate.

How CAS affects e-invoicing and the new CWT field

This is where many CAS users get caught out. The rules separate registering a system from being allowed to issue e-invoices with it.

• Your AC is not a PTI. RMC No. 98-2026, dated September 22, 2026, states that the PTI is distinct from the PTU or AC for CAS. The AC authorizes use of the system but isn't, by itself, authority to issue electronic invoices.
• CAS and CBA users with e-invoicing are covered. Coverage includes taxpayers using CAS or CBA with electronic invoicing and other invoicing software, along with e-commerce businesses (except Micro), Large Taxpayers and others the Commissioner names. Covered taxpayers, except Micro, must issue e-invoices by December 31, 2026.
• A printout isn't an e-invoice. Invoices generated by a CAS or CBA and printed on paper don't count as electronic invoices if the system can't issue and transmit them to the buyer electronically.
• Changing systems means a new PTI. Any change in the identity, platform or core details of your e-invoicing system, including migrating to new software, requires a new or amended PTI.
• The CWT field has its own deadline. RR No. 6-2026 requires CWT to be shown as a separate item on invoices when the sale is subject to it. Under RMC No. 112-2026, CAS/CBA and invoicing software covered by mandatory e-invoicing must support the CWT field by December 31, 2026. Until then you can stamp or write it on CWT transactions. Read our guide to CWT on invoices.
• POS users follow a parallel track. If you sell through POS terminals, see our companion guide to POS and CRM compliance and eSales.

Watch out: Software marketed as "BIR-accredited" or "CAS-ready" doesn't register you. The AC is issued to your business, for your specific system and setup. You still need your own AC, and your own PTI if you issue e-invoices.

Ongoing compliance

Annual registration of e-books

RMC No. 3-2023 requires computerized books to be registered within 30 days from the close of each taxable year, or within 30 days from the closure of operations, whichever comes first. The deadline can be extended only if you request it before it lapses. RMC No. 4-2026 made ORUS filing mandatory and moved the taxable year 2025 deadline from January 30 to February 17, 2026 because of ORUS log-in problems. That extension was a one-time move, so plan on January 30 for calendar-year books. If your books were registered before the audit was finished, RMO No. 9-2021 says you submit the auditor's adjustments in soft copy.

System changes

Using an upgraded system without informing the BIR exposes you to penalties, and RMC No. 5-2021 says an existing PTU can be automatically revoked in that case.

Retention

The EOPT Act (Republic Act No. 11976) amended Section 235 of the Tax Code. Books and records must be kept for five years, counted from the day after the filing deadline for the taxable year of the last entry, or from the actual filing date if you filed late. Under RR No. 7-2024, computerized books are preserved as electronic copies. Keep records longer if they relate to a pending protest or refund claim. RMO No. 9-2021 mentions ten years for users of tax service providers, citing RR No. 5-2014, but that rule predates the EOPT Act. When in doubt, keep more.

Inventory and branches

If inventory matters to your business, make sure the inventory book is among the books declared in your Annex C-1 and that it reconciles to your financial statements. New branches using the same registered system should be reflected in your AC's list of branches. For e-invoicing, a new branch on the same approved system doesn't need a new PTI number, but you must notify the BIR.

Advantages of CAS

• Less paperwork. No binding of printouts, and no handwritten journals. Your e-books are registered online once a year.
• Faster closing and reporting. Ledgers, VAT summaries and financial statements come straight from the system.
• E-invoicing ready. A CAS that issues e-invoices puts you on the path the BIR now requires for covered taxpayers.
• Better controls. Audit trails, user access and automatic numbering reduce errors and make audits smoother.
• Room to grow. Adding branches, users and integrations is easier than with manual or loose-leaf books.

Disadvantages of CAS

• Recurring software costs. Subscriptions and e-invoicing add-ons are monthly expenses that rise as you add users.
• Upfront documentation. The sworn statement and annexes take real effort, especially for custom or integrated systems.
• Change control. Major software updates may require re-registration, which you don't fully control when a cloud vendor pushes updates.
• Vendor dependence. If your provider contract ends, your registration ends with it. You need export rights to your data.
• Post-evaluation risk. There's no demonstration before approval, but the BIR checks later. What you declared must match what you actually run.

Frequently asked questions

Do I still need a Permit to Use for my computerized accounting system?

No, not for new registrations. RMC No. 5-2021 and RMO No. 9-2021 replaced the PTU with an Acknowledgement Certificate issued within three working days of complete documents. A PTU issued before then remains valid unless it is revoked or you make a major system enhancement, in which case you apply for a new AC.

Is CAS registration mandatory for small businesses?

No. CAS is mandatory for Large Taxpayers. Other businesses may choose manual, loose-leaf or computerized books. But if you use software to generate your books or invoices, you must register it before use.

How much does BIR CAS registration cost?

The BIR charges no fee for the Acknowledgement Certificate or for the yearly registration of computerized books, according to the 2025 Citizen's Charter. Your costs are software subscriptions, notarization and any professional help. Budget roughly ₱5,000 to ₱120,000 in the first year, depending on your plan and setup.

Can I register QuickBooks, Xero or another cloud system as my CAS?

Yes. RMO No. 9-2021 covers off-the-shelf and cloud systems. The registration is for your business and your setup, not for the software itself. When a third-party provider supplies or runs the system, you and the provider sign a joint sworn statement.

Does having a CAS mean I'm compliant with e-invoicing?

Not automatically. Under RMC No. 98-2026, you need a separate Permit to Issue Electronic Invoice and an EIS Certification within six months of the PTI. Your system must also issue and transmit invoices electronically, not just print them.

When do I submit my computerized books each year?

Register them through ORUS within 30 days after the close of your taxable year, which is January 30 for calendar-year taxpayers. For taxable year 2025, RMC No. 4-2026 extended the deadline to February 17, 2026. Print and keep the QR stamp ORUS generates.

What happens if I upgrade my accounting software?

It depends on the change. Major enhancements that affect financial computations, modules or versions need a new application and a new AC before use. Minor changes such as bug fixes or interface updates need only a written notice to your RDO.

How Upcloud can help

We handle BIR system registration end to end, from preparing your sworn statement and annexes and filing in ORUS to securing your PTI for e-invoicing and registering your e-books each year. If you're choosing between loose-leaf and CAS, or migrating software before the December 31, 2026 deadline, we can map the right path for your business. See our business processing and tax compliance services, or contact us for a short consultation.

References

1. Bureau of Internal Revenue. Revenue Memorandum Order No. 9-2021: Prescribing the Simplified Guidelines and Procedures on the Use of Computerized Accounting System (CAS), Computerized Books of Accounts (CBA), and/or its Components. February 1, 2021. https://bir-cdn.bir.gov.ph/local/pdf/RMO%20No.%209-2021.pdf
2. Bureau of Internal Revenue. Revenue Memorandum Circular No. 5-2021: Simplified Policies on the Application for Registration of CAS, CBA and/or its Components. January 8, 2021. https://bir-cdn.bir.gov.ph/local/pdf/RMC%20No.%205-2021.pdf
3. Bureau of Internal Revenue. Citizen's Charter (2025 Edition): Processing of Application for Registration of CAS, CBA and Components, including through ORUS. 2025. https://bir-cdn.bir.gov.ph/BIR/pdf/BIR%20Citizen%27s%20Charter%20%282025-Edition%29.pdf
4. Bureau of Internal Revenue. Checklist of Documentary Requirements (Revised July 2025). 2025. https://bir-cdn.bir.gov.ph/BIR/pdf/CDR%20-%202025%20%281%29.pdf
5. Bureau of Internal Revenue. Revenue Memorandum Circular No. 3-2023: Policies and Guidelines on the Online Registration of Books of Accounts. January 10, 2023. https://bir-cdn.bir.gov.ph/local/pdf/RMC%20No.%203-2023.pdf
6. Bureau of Internal Revenue. Revenue Memorandum Circular No. 4-2026: Clarification on the Mandatory Registration of Permanently Bound Loose-Leaf Books of Accounts and Computerized Books of Accounts Through ORUS, and Extension of Registration Deadlines. January 15, 2026. https://bir-cdn.bir.gov.ph/BIR/pdf/RMC%20No.%204-2026.pdf
7. Bureau of Internal Revenue. Revenue Memorandum Circular No. 65-2025: Clarification on the Registration of Books of Accounts for New Business Registrants. July 2, 2025. https://bir-cdn.bir.gov.ph/BIR/pdf/RMC%20No.%2065-2025.pdf
8. Bureau of Internal Revenue. Revenue Memorandum Circular No. 98-2026: Policies and Guidelines on the Issuance of Electronic Invoice. September 22, 2026. https://bir-cdn.bir.gov.ph/BIR/pdf/RMC%20No.%2098-2026%20redacted.pdf
9. Bureau of Internal Revenue. Revenue Memorandum Circular No. 112-2026: Clarifying RR No. 006-2026 on the Separate Presentation of Creditable Withholding Tax in Sales Invoices. October 22, 2026. https://bir-cdn.bir.gov.ph/BIR/pdf/RMC%20No.%20112-2026_redacted.pdf
10. Bureau of Internal Revenue. Revenue Regulations No. 6-2026: Including Creditable Withholding Tax Information in the Mandatory Invoice Information. 2026. https://bir-cdn.bir.gov.ph/BIR/pdf/RR%20No.%206-2026.pdf
11. Bureau of Internal Revenue. Online Registration and Update System (ORUS). https://orus.bir.gov.ph
12. Bureau of Internal Revenue. EIS Certification Portal. https://eis-cert.bir.gov.ph
13. Lawphil. Republic Act No. 11976 (Ease of Paying Taxes Act), Section 33 amending Section 235 of the Tax Code. January 5, 2024. https://lawphil.net/statutes/repacts/ra2024/ra_11976_2024.html
14. P&A Grant Thornton. EOPT on Computerized Accounting System (CAS): To secure or not to secure new Acknowledgment Certificate. July 9, 2024. https://www.grantthornton.com.ph/insights/articles-and-updates1/lets-talk-tax/eopt-on-computerized-accounting-system-cas-to-secure-or-not-to-secure-new-acknowledgment-certificate/
15. P&A Grant Thornton. EOPT is here: Updates on the preservation of book of accounts and changes in taxpayer registration. May 27, 2024. https://www.grantthornton.com.ph/insights/articles-and-updates1/tax-notes/eopt-is-here-updates-on-the-preservation-of-book-of-accounts-and-changes-in-taxpayer-registration/
16. Reyes Tacandong & Co. Tax Tweets, October 2025 (summary of RMC No. 65-2025). October 2025. https://www.reyestacandong.com/wp-content/uploads/2025/10/Tax-Tweets-October-2025.pdf
17. Xero. Upcoming Xero price changes (Philippines). 2026. https://www.xero.com/ph/pricing-plans/update/