I. Overview and Policy Context

The Philippines’ SIM Registration Act (Republic Act No. 11934) requires all Subscriber Identity Module (SIM) cards—whether prepaid or postpaid—to be registered to an individual or juridical entity. The law’s objectives include reducing scams, text fraud, anonymous threats, and other crimes facilitated through unregistered or falsely registered SIMs.

A lost or stolen SIM creates heightened legal and practical risks: the card may be used for fraud, identity theft, or criminal activity under the registered owner’s name. The SIM Registration Act and its Implementing Rules and Regulations (IRR) therefore recognize a subscriber’s right to report loss and request deactivation to protect themselves and preserve the integrity of the registry.

II. Key Legal Framework

Republic Act No. 11934 (SIM Registration Act)
- Mandates SIM registration prior to activation and ongoing accuracy of subscriber data.
- Requires Public Telecommunications Entities (PTEs) to maintain secure SIM registries.
- Provides penalties for misuse, fraudulent registration, and failure to comply.
Implementing Rules and Regulations (National Telecommunications Commission)
- Detail procedures for registration, data updates, and deactivation.
- Assign PTEs responsibility for help desks and subscriber support.
Data Privacy Act of 2012 (RA 10173)
- Applies to the collection and processing of SIM registration data.
- Requires PTEs to safeguard personal information and process only what is necessary.

III. What “Deactivation” Means in This Setting

Under Philippine telecom practice aligned with the SIM Registration Act, deactivation of a lost SIM generally refers to the PTE’s act of disabling the SIM from accessing the network, preventing further calls, texts, mobile data use, and related services.

Deactivation serves distinct functions:

Security: stops unauthorized use.
Compliance: keeps the SIM registry accurate and prevents registered users from being tied to activities they did not commit.
Precondition to Replacement: often required before issuance of a replacement SIM with the same number.

Deactivation is different from:

Blocking: a network-level suspension due to fraud or non-registration.
Number recycling: reassignment of long-inactive numbers, which happens only after specific inactivity periods under PTE internal policies.

IV. Your Rights and Duties When a SIM is Lost

A. Rights

Right to report loss and request deactivation.
Right to replacement (subject to PTE policies and identity verification).
Right to update personal data if needed to facilitate replacement.
Right to privacy and secure handling of your data.

B. Duties

Prompt reporting. The law expects subscribers to help keep the registry accurate; delay may increase your risk.
Truthful and complete information. False reporting may expose you to liability.
Compliance with verification. PTEs may require proof of identity before deactivation or replacement.

V. Standard Procedure to Deactivate a Lost SIM Card

While exact steps differ slightly by telco, the legally compliant structure is consistent:

Step 1: Report the Loss Immediately

You may report through:

Official hotline / customer service number
Physical store or service center
Official app or online portal (if offered)

At this stage, you are typically asked for:

Your full name
Mobile number
Date/time and circumstances of loss
Registered details (birthday, address, etc., as on record)

Step 2: Undergo Identity Verification

PTEs must ensure that only the registered owner or authorized representative can deactivate a SIM.

Verification usually includes:

Presentation or upload of a valid government ID
Matching of your submitted information with the SIM registry
Possible selfie/biometric check in apps or store kiosks
Security questions or one-time password to linked accounts (if still accessible)

Authorized representatives of a subscriber (e.g., family member, corporate officer) may be allowed to request deactivation, depending on PTE policy, often requiring:

Authorization letter or special power of attorney
Representative’s valid ID and the subscriber’s ID copy
Registry matching

Step 3: Submit a Deactivation Request

Once verified, you formally request:

Immediate SIM deactivation due to loss or theft.
If desired, you may also request number retention and replacement.

The PTE should log your request and provide a reference number or confirmation.

Step 4: Confirm Deactivation

Deactivation is typically immediate or near-immediate. Confirmation may appear as:

SMS/email to your registered alternate contact
App notification
Store receipt or ticket

If the SIM was used for suspicious activity before deactivation, keep your case reference.

VI. Replacement After Deactivation (Same Number)

Most subscribers want to keep their number. Under the SIM Registration framework, replacement is generally allowed if:

You are the registered owner; and
You pass identity verification; and
The SIM is confirmed lost/stolen and now deactivated.

Replacement requests often require:

Valid ID (same as used in registration)
Affidavit of Loss (commonly required; telco practice varies)
Payment of replacement fee (if applicable)
Completion of a replacement form

Result: You get a new SIM tied to your old number, and the registration data carries over or is revalidated by the PTE.

VII. Special Considerations

A. Prepaid SIMs

Prepaid users are fully covered by the SIM Registration Act.
Deactivation and replacement may require stricter proof because prepaid accounts often lack billing records.

Helpful evidence:

Screenshot of original registration confirmation
Proof of ownership via linked e-wallets, apps, or OTP history
PTE account credentials if you registered online

B. Postpaid SIMs

Easier verification through account records and billing.
Replacement usually processed at stores or via account hotlines.
If your phone is also postpaid and lost, you may need to request device/IMEI blacklisting separately.

C. SIMs Registered to Corporations (Juridical Entities)

Deactivation must be requested by:

Authorized corporate officer; or
Duly authorized representative.

Required:

Company documents proving authority (e.g., secretary’s certificate)
IDs of officer/representative
Corporate SIM registry details

D. Minors

SIMs registered to minors are usually under a parent/guardian record. Deactivation is requested by the parent/guardian who completed the registration.

VIII. Evidence and Documentation

To protect yourself legally and practically, keep:

Deactivation case/reference number
Affidavit of Loss (if required or if there is fraud risk)
Screenshots/emails confirming SIM registration
Any fraud-related messages or call logs before deactivation
Police report (optional, but recommended if theft is linked to scams, extortion, or financial loss)

These help in:

Disputing liability if crimes occur using your number
Accelerating replacement
Supporting complaints before the NTC or law enforcement

IX. Liability and Risk Management

A. If the Lost SIM Is Used for Crime

A registered SIM ties activity to you in the registry, but registration is not conclusive proof of guilt. Still, you may be questioned. Prompt deactivation and clear records of reporting help demonstrate good faith and non-involvement.

B. Failure to Report

The Act emphasizes registry accuracy. While the law primarily penalizes fraudulent or unregistered use, delay in reporting can worsen your exposure in practical investigations.

X. Remedies if the Telco Refuses or Delays Deactivation

If a PTE unreasonably refuses to deactivate after you prove ownership:

Escalate internally
- Supervisor channels
- Store manager
- Official complaint email
File a complaint with the NTC
- Provide your reference number, narrative, IDs, proof of registration, and any evidence of harm.
Data Privacy complaint (if your personal data is mishandled)
- May be filed with the National Privacy Commission.

XI. Interaction with Banking, E-Wallet, and Online Accounts

Because mobile numbers are widely used for OTPs and account recovery:

Notify banks/e-wallet providers immediately.
Freeze or update OTP channels if possible.
Change passwords on linked accounts.
Update recovery numbers once replacement SIM is active.

This is not a SIM Registration Act requirement, but it is crucial to reduce cascading harm.

XII. Practical Checklist

If your SIM is lost:

Report to telco immediately.
Prepare valid ID used in registration.
Request deactivation and get a reference number.
File an Affidavit of Loss if required.
Request replacement with same number (if desired).
Inform banks/e-wallets and secure online accounts.
Keep documentation in case of later investigation.

XIII. Common Questions

1. Can someone else deactivate my SIM? Only if they are an authorized representative and can prove authority per PTE policy.

2. Do I need an affidavit of loss? Often yes for replacement, not always for immediate deactivation. Telcos may still request it as part of verification.

3. Will deactivation delete my registration? No. The SIM is disabled, but your registration record remains tied to your identity and the number, especially if you seek replacement.

4. Can I reactivate the same SIM if I find it later? Usually no. Once a SIM is replaced or permanently deactivated, telcos require continued use of the new SIM for security and registry integrity.

XIV. Conclusion

Under the SIM Registration Act, deactivating a lost SIM is both a right and a responsible step that protects you and supports the law’s anti-fraud goals. The core legal logic is simple: the registry must remain accurate, and access to a lost SIM must end quickly.

Act fast, verify ownership through your telco’s process, secure a deactivation confirmation, and follow through with replacement and account-security measures.