Hong Kong-invested mobile operator Vietnamobile has been asked to stop issuing new ‘Thanh SIM’ prepaid SIM cards in Vietnam, less than two months after the product’s January launch.

The Thanh SIM promotion package shows “signs of violating regulations on telecom pricing control,” according to Vietnam National Telecommunications Administration (VNTA), which made the request.

The Thanh SIM was introduced to the market in January 2018, followed by a grand TVC launch in Ho Chi Minh City in February where Vietnamobile unveiled a television commercial for the "unbelievable" product.

For just VND40,000 (US$1.76), customers who purchase the SIM can access unlimited data by simply topping up their account with a monthly minimum of VND20,000 ($0.88).

In addition to data, Thanh SIM also has the lowest voice tariff in the market at justVND680 per minute for both on-net and off-net calls.

VNTA has demanded that Vietnamobile stop issuing new Thanh SIM cards and submit a full report on the product by March 13.

The mobile operator is expected to report on the current number of Thanh SIM subscribers, how the discontinuation will affect its revenue, and what back-up plans it has in place.

Vietnamobile, a joint venture between Hanoi Telecom Corporation and Hong Kong-based Hutchison Asia Telecommunications Limited, is the only mobile telecom operator in Vietnam currently receiving foreign investment.

It is the fourth-largest mobile operator in the country by brand value, according toBrand Finance’s 2017 Telecom 500 annual report on the world’s most valuable telecom brands.