Banks in Nigeria have introduced service charge on USSD services. This was made known through SMS sent out to MTN customers. See Snapshot below:



In response to a customer's enquiry, MTN Ngeria through their official twitter handle informed customers on the new development.....Read response below:

Y'ello, Thank you for reaching out. kindly be informed that you will be charged N4.00 for all bank transactions using USSD codes. This is a directive from your various financial institutions. Kindly contact your bank for further enquiries. Thank you.

Unstructured Supplementary Service Data (USSD) is a protocol used by GSM cellular telephones to communicate with the service provider's computers. USSD can be used for WAP browsing, prepaid callback services, mobile-money services, location-based content services, menu-based information services, and as part of configuring the phone on the network.

According to the CBN, Service providers that provide financial services through the use of USSD in Nigeria
include the following:

a. Financial institutions: Banks, Other Financial Institutions and Payment Service Providers, providing products and services using USSD protocol to their customers.
b. Mobile Money Operators (MMOs): MMOs are Deposit Money Banks or corporate entities, duly licensed by the CBN to provide mobile payment services to the banked and unbanked customers.

c. Mobile Network Operators (MNOs): MNOs utilize USSD to interact with, and provide services to their customers.
d. Value Added Service Providers/ Aggregators (NCC Licensees) – Any person or organization that engages in the provision of value added mobile/fixed Services, including premium rated services.

e. Customers: initiate financial transactions or sessions through a USSD string provided by their financial Institutions

Source - https://news.assure.ng/breaking-nigerian-banks-to-charge-for-ussd-services/