A disturbing trend in which bank customers are losing money through fraudulent activities involving recycled phone numbers and Unstructured Supplementary Service Data (USSD), highlights vulnerabilities in the synergy between banks and telecommunications companies.

According to a report by the Foundation for Investigative Journalism (FIJ), if a Nigerian telephone number connected to a Nigerian bank account for USSD, is not used for a while, the network provider can disconnect the original owner and sell the number to someone else, and that person would be able to access money via USSD from the original owner?s account.

Those were the words of Elizabeth ?Kandi, a UK-based medical doctor, as she shared a friend?s experience on X in May.

Her friend?s phone line had been inactive for a while and was eventually recycled, so this allowed a new user to gain access to the number after purchasing a new SIM card.

According to the post on May 13, 2025, Dr. Elizabeth ?Kandi/X, Nigerian network providers such as MTN, GLO, Airtel and 9mobile are allowed to recycle phone numbers that have been inactive over a specific period.

Of these four network providers, only MTN responded to media inquiry via email. This network provider explained that when a SIM is terminated due to its dormant status, recycled and sold to another customer, such a line cannot be retrieved by the old owner or reversed to him/her.

?However, the new user does not have access to the old user?s bank account. All you need to do is to contact your financial institutions about the status of the line and inform them to remove it from your banking details to prevent unauthorised access to your financial information as MTN would not be liable for any fraudulent transaction that may occur on the line as a result of your failure to instruct your bank accordingly,? MTN?s response read in part.

Based on the provisions of the Quality of Service Business Rules issued by the Nigerian Communications Commission (NCC) in 2024, a phone number may be deactivated if it has not partaken in any revenue-generating event (RGE) within six months.

RGE includes outgoing and incoming voice calls, subscription to any voice plan or any plan that gives voice access to a subscriber for a specific period, outgoing and incoming Short Message Service (SMS) and Multimedia Messaging Service (MMS), mobile data usage and USSD transactions, among others.

If this continues for another six months, the subscriber may lose the phone number, as it has now become eligible for churning (also called recycling). The only exception is if a network-related issue prevents the line from generating revenue.

Because even NIN-linked SIMs can be deactivated, the network providers offer paid services that allow users who are travelling out of the country to retain their numbers and stay active for at least a year. This can help reduce the chances of a number being recycled or sold to someone else. While MTN and Airtel offer options up to three years, GLO allows this for 365 days.

FIJ quoted sources within the NCC as having said that mobile network operators are free to churn inactive lines and put them back into the market.

Ideally, a network provider?s decision to recycle a dormant line should not raise concerns. However, the experiences of subscribers like Kandi?s friend show that Nigerians risk financial loss and even identity theft due to lapses in the recycling process.

There are no measures in place to purge old users? data from inactive lines before this churning takes place.

For instance, in the doctor?s friend?s case, the new user capitalised on the fact that the line was linked to its previous user?s bank account to steal from them by recharging via an Unstructured Supplementary Service Data (USSD) code.

Since the new user recharged the linked number directly, they weren?t required to provide a PIN to complete the transaction. On the occasion that a one-time password (OTP) is required, the OTP would appear on the same line.

Findings show that some bank customers started receiving bank alerts meant for the previous owners of the phone numbers after getting new SIM cards. Others shared how the new users of their recycled numbers stole from them, and their banks could not recover the money.

Some also warned that things could get worse, since important details like their National Identification Number (NIN) and Bank Verification Number (BVN) are linked to those phone numbers.

Ayomi (surname withheld), who shared her experience, said she woke up to emails of some deductions from her GTBank account on March 13, 2023. When she notified her bank?s e-fraud team, her account was restricted, but she still got another debit alert. The new subscriber who had the recycled phone number that was linked to her bank account took N100,000 in total.

?On March 16, N50,000 was refunded out of the N100,000. About seven or eight months later, the remaining N50,000 was refunded. That same year, I travelled back home and changed my ATM card and phone number details because the phone number had been transferred to another person. I still use it for my WhatsApp, but I no longer have any financial details attached to the number,? she narrated.

In 2020, the Department of State Services (DSS) arrested and detained Anthony Okolie for buying and using an MTN SIM card previously used by the daughter of former president Muhammadu Buhari.

Local reports said the number was recycled and put back on the market after it was abandoned by the former president?s daughter. When Okolie purchased a SIM card, it turned out to be the same line. The DSS did not confirm if Okolie misused the SIM or committed any crime with the phone number.

On why inactive phone numbers are recycled, an NCC source, who does not want to be named, said that numbering resources such as telephone numbers and short codes are the backbone of modern telecommunications.

?They are governed globally by the International Telecommunication Union (ITU) under Recommendation E.164, which ensures efficiency and equitable access to numbers across borders,? they said.

According to the NCC source, the numbering resources are ?inherently scarce?. Because each number must conform to a fixed length and format, it yields only a finite set of valid combinations.

?The NCC assigns number ranges to licensed operators and services (mobile, fixed, and special) in a manner that promotes fair competition, protects consumers, fosters innovation, and aligns with ITU standards and global best practices,? the NCC source explained.

They, however, acknowledged that recycling phone lines comes with challenges, particularly when the previous owners still have their old numbers linked to services they used before SIM reassignment.

?This presents issues of security and integrity of phone number ownership,? the source disclosed.

The NCC seeks to address these concerns by developing a cross-sector platform that will collect and share data on recycled phone numbers. The platform will also identify numbers that have been flagged for fraudulent activities, as reported by other sector regulators.

Insiders said the Commission was working with the Central Bank of Nigeria (CBN), security agencies and other critical stakeholders to test a beta solution to the problem.

?The goal is to prevent the misuse of numbers when they change hands. The information on this platform will be made available to relevant stakeholders across various sectors. The NCC will host the platform and establish its regulatory and operational framework,? the NCC insider revealed. (Nigerian Tribune)

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