South Carolina taxpayers will have until Oct. 15 to file their 2025 state individual income tax returns as lawmakers continue considering House Bill 3368, which includes South Carolina’s 2025 income tax conformity update and provisions related to overtime and certain bonus pay.
The South Carolina Department of Revenue announced March 26 that it is automatically extending the filing deadline for all 2025 South Carolina individual income tax returns from April 15 to Oct. 15, 2026, citing uncertainty surrounding H. 3368, which remains pending in the Senate. No action is required to receive the filing extension, the agency said.
The extension applies only to filing, not payment.
The department said taxpayers must still pay at least 90% of their 2025 state tax liability by April 15 to avoid penalties. Taxpayers expecting refunds need only file by the new Oct. 15 deadline.
H. 3368 includes South Carolina’s annual tax conformity update and would also exclude certain overtime and bonus pay from taxable income. The bill would update the state’s tax code to match the current Internal Revenue Code through Dec. 31, 2025, allowing South Carolina to recognize certain federal deductions and exclusions enacted under the federal One Big Beautiful Bill Act for the 2025 tax year.
Among the changes under discussion is a state income tax exemption for overtime earnings. An earlier House version of the bill specifically proposed exempting overtime pay and the first $2,500 in annual bonus compensation from taxable income, while reporting by The State noted lawmakers have also debated federal provisions affecting up to $12,500 in overtime pay and up to $25,000 in tips. Exactly how those provisions would apply remains unclear while the bill is still pending in the Senate.
As of Thursday, the bill had received a favorable report from the Senate Finance Committee but had not yet received final Senate approval. If it becomes law, the SCDOR said it will issue additional guidance, including for taxpayers who have already filed 2025 returns.
The State also reported that more than 1.2 million South Carolina income tax returns had already been filed as of March 12, raising questions about whether some taxpayers may need to amend returns if the legislation becomes law. The department has not yet said how it would handle taxpayers who have already filed, paid balances due or received refunds.
The SCDOR said it will continue posting updates and taxpayer guidance through its website and social media channels.
