2025, compared to a $1.4 million loss for the three months ended June 30, 2024. Non-interest income was also impacted by a $281 thousand increase in payment processing income, $193 thousand increase in commercial loan fees and $143 thousand increase in swap fees for the three months ended June 30, 2025.
Non-interest income decreased $370 thousand, or 4.0%, to $9.0 million for the six months ended June 30, 2025, from $9.3 million for the six months ended June 30, 2024. The decrease was primarily due to a $1.6 million decrease in net gains on equity securities, from no gains for the six months ended June 30, 2025, compared to a $1.6 million gain for the six months ended June 30, 2024. The decrease was also due to a $747 thousand decrease in net loss on securities available for sale, from losses of $619 thousand for the six months ended June 30, 2025, compared to a $1.4 million loss for the six months ended June 30, 2024. Non-interest income was also impacted by a $356 thousand write-down of equipment no longer in use and a $498 thousand decrease in the valuation of mortgage servicing rights for the six months ended June 30, 2025, compared to June 30, 2024, resulting from a decline in market interest rates. This was partially offset by a $611 thousand increase in payment processing income and a $250 thousand gain on the sale of the Direct Merchant Processing Book for the six months ended June 30, 2025.
Non-interest Expense. Non-interest expense increased $800 thousand, or 4.2%, to $19.8 million for the three months ended June 30, 2025, from $19.0 million for the three months ended June 30, 2024. Data processing costs increased $776 thousand, or 35.0%, primarily due to the new on-line banking platform, increased account volume and licensing costs. All other non-interest expenses increased $24 thousand, or 0.1%, to $16.8 million for the three months ended June 30, 2025, from $16.7 million for the three months ended June 30, 2024, due to higher salaries and employee benefits, higher consulting expenses, and lower occupancy and equipment expense.
Non-interest expense increased $4.5 million, or 12.2%, to $41.6 million for the six months ended June 30, 2025, from $37.1 million for the six months ended June 30, 2024. Salary and employee benefit expenses increased $3.2 million, or 18.3%, primarily due to a $756 thousand increase in the long-term incentive expense which was primarily the result of the termination of the plan and immediate vesting of participants, a $1.3 million increase in short-term incentives, payroll taxes and retirement expenses, and a $879 thousand increase in salaries. Data processing costs increased $1.9 million, or 44.1%, primarily due to a new on-line banking platform, increased account volume and licensing costs, and one-time expenses of $379 thousand related to contract terminations. All other non-interest expenses decreased $580 thousand, or 3.8%, to $14.7 million for the six months ended June 30, 2025, from $15.3 million for the six months ended June 30, 2024, due to lower occupancy and equipment expense and the sale of the credit card portfolio.
Income Tax Benefit/Expense. Income tax expense was $1.2 million for the three months ended June 30, 2025, compared to an income tax expense of $759 thousand for the three months ended June 30, 2024. The effective tax rate was 23.0% and 24.4% for the three months ended June 30, 2025, and June 30, 2024, respectively.
Income tax benefit was $3.8 million for the six months ended June 30, 2025, compared to an income tax expense of $2.0 million for the six months ended June 30, 2024. The effective tax rate was 32.8% and 25.1% for the six months ended June 30, 2025, and June 30, 2024, respectively.
Liquidity and Capital Resources
Liquidity describes our ability to meet the financial obligations that arise in the ordinary course of business. Liquidity is primarily needed to meet the borrowing and deposit withdrawal requirements of our customers and to fund current and planned expenditures. Our primary sources of funds are deposits, principal and interest payments on loans and securities, and proceeds from maturities of securities. In addition, we have available credit facilities with the Federal Home Loan Bank of Boston, correspondent banks, and the Federal Reserve Bank of Boston. At June 30, 2025, we had the ability to borrow $680.4 million from the Federal Home Loan Bank of Boston, of which $260.0 million was outstanding. At June 30, 2025, we also had a $500 thousand line of credit with the Federal Home Loan Bank of Boston with no borrowings outstanding. At June 30, 2025, we had $18.0 million of available lines of credit with correspondent banks with no borrowings outstanding under any of them. At June 30, 2025, we also had aggregate available borrowing capacity of $324.1 million through the discount window and the borrower-in-custody program at the Federal Reserve Bank of Boston with no borrowings under either facility.
While maturities and scheduled amortization of loans and securities are predictable sources of funds, deposit flows and loan prepayments are greatly influenced by interest rates, economic conditions, and competition. Our most liquid assets are cash and short-term investments. The levels of these assets depend on our operating, financing, lending, and investing activities during any given period.