Overall revenue from our Taiwan segment increased by $1.4 million from $27.0 million for the three months ended March 31, 2020 to $28.5 million for the three months ended March 31, 2021. Due to our continued growth in the sales of insurance products in the past years, we continue to receive more contingent commissions, which include trailing commissions, persistency rate linked bonuses and some other service allowance, for the three months ended March 31, 2021. However, the revenue growth was partially offset by decreases in the sales of long-term care and disability insurance products because of the discontinuations of these products in the year 2020.
Overall revenue from our PRC segment increased by $0.5 million to $2.0 million for the three months ended March 31, 2021 from $1.4 million for the three months ended March 31, 2020. Such increase in revenue of the PRC segment was mainly due to the adverse impact on the outbreak of COVID-19 that restricted to a significant extent our sales agents’ in-person selling activities in the first quarter of 2020. The operations in the PRC segment had been fully resumed in the second quarter of 2020.
The revenue in the Hong Kong Segment was primarily derived from reinsurance commission on sales of insurance products from other insurers to Taiwan Life Insurance Co., Ltd. (“Taiwan Life”) for risk management. Overall revenue from our Hong Kong segment for the three months ended March 31, 2021 remained consistent with the same period in 2020.
Cost of revenue and gross profit
The cost of revenue mainly consists of commissions paid to our sales professionals. The cost of revenue for the three months ended March 31, 2021 decreased by $0.5 million, to $19.0 million compared to $19.5 million for the three months ended March 31, 2020. Decreases in the cost of revenue were due to fewer insurance policies sold during the first quarter of 2021 compared to the same period of 2020, which result in a decrease in the direct commission costs paid to sales professionals for the first-year commissions.
Consequently, the gross profit margin increased from 31.6% for the three months ended March 31, 2020 to 37.9% for the three months ended March 31, 2021.
Selling expenses
Selling expenses were mainly incurred by Law Broker and Uniwill in connection with online marketing and advertising. Overall selling expenses for the three months ended March 31, 2021 remained consistent with the same period in 2020.
General and administrative expenses
General and administrative (“G&A”) expenses are principally comprised of salaries and benefits for our administrative staff, office rental expenses, travel expenses, depreciation and amortization, entertainment expenses, and professional service fees.
For the three months ended March 31, 2021, our G&A expenses were $6.1 million, reflecting a decrease of $0.9 million, compared with $7.0 million for the three months ended March 31, 2020. Our G&A expenses decreased for the three months ended March 31, 2021 because the Company recognized costs of $1.0 million related to stock-based compensation arrangements during the first quarter of 2020.
Other income (expenses)
Other income (expense) mainly consisted of interest income, interest expenses, gain or loss on valuation of financial assets, and foreign currency exchange gain or loss. Net other income for the three months ended March 31, 2021 was $0.5 million, reflecting an increase of $0.7 million, compared with net other expense of $0.1 million for the three months ended March 31, 2020. The increases in other income for the three months ended March 31, 2021 was due to foreign currency exchange gain recognized because of the depreciation of the New Taiwan Dollar against the US dollar during the first quarter of 2021.
Income tax expense
For the three months ended March 31, 2021, income tax expense was $1.4 million, reflecting an increase of 25.9%, compared with the income tax expense of $1.1 million for the three months ended March 31, 2020. The increase was mainly due to more taxes on undistributed earning accrued because of more revenues generated in the Taiwan segment during the first quarter of 2021.