Key takeaways
- Georgia Form 600S for tax year 2026 is due March 15, 2027, a Monday, unless a timely extension applies.
- A federal Form 7004 or Form 8868, or a Georgia Form IT-303, filed by the original due date gives 7 months, to October 15, 2027.
- An extension moves the filing date only. Estimate the Georgia tax and prepay with Form IT-560C by March 15, 2027.
- Each nonresident shareholder must sign Form 600S-CA by March 15, 2027, or the company withholds or elects composite for that owner.
What Form 600S covers and what to collect first
Form 600S is Georgia’s income tax return for an S corporation, filed for the same tax year as the federal Form 1120-S. The most recent Department booklet I could read is the 2024 S Corporation Income Tax General Instructions (IT 611S, Rev. 10.09.24). Pull the 2026 edition before you file.
Collect three things first: the shareholder list with each owner’s 2026 state of residence, each owner’s Georgia share of income, and the federal Schedule K-1 amounts. The booklet also requires a complete copy of the federal return and all supporting schedules to be attached to the Georgia return.
The due date for tax year 2026
The Department’s corporate due dates page says S corporation returns (600S) are due “on or before the 15th day of the third month following the close of the taxable year.” For a calendar-year company that is March 15, 2027, a Monday. If the due date falls on a weekend or holiday, the return is due the next day that is not a weekend or holiday.
The federal date works the same way. The IRS instructions for Form 1120-S give the example that the due date was “March 16, 2026 (March 15th falls on Sunday)” for the 2025 return. The 2026 federal return is due March 15, 2027.
Failure mode: last year’s calendar entry gets copied forward. Fix: write the tax year into each entry and check the weekday for that year.
How the Georgia extension works
Under O.C.G.A. 48-7-57, a taxpayer does not need a separate Georgia application if it receives the automatic six (6) month federal extension. The Department says a federal Form 7004, a Form 8868 or a Georgia IT-303 filed by the original due date grants “an additional 7 months.” Georgia law prohibits an extension of more than seven months from the due date. For tax year 2026 the Georgia filing date moves from March 15, 2027 to October 15, 2027.
Path A is the federal Form 7004, filed by March 15, 2027. The IRS instructions say properly filing Form 7004 gives the maximum extension allowed. For Form 1120-S that is six months, to September 15, 2027, and the Georgia return follows on its own seven-month window. Path B is Form IT-303, used when no federal extension is filed. Path A is the usual choice, because the Georgia return needs final federal numbers anyway.
Keep the IRS acceptance for Form 7004 in the workpapers. On page 1 of Form 600S, check the Extension box.
The extension moves the filing date, not the payment
The booklet says an extension “does not alter the interest or penalty charge for late payment of tax,” and interest runs from the statutory due date regardless. An extended taxpayer must prepay the Georgia tax with Form IT-560C and claims the prepayment on Form 600S, Schedule 4, Line 2.
Late payment penalties apply at 1/2 of 1% per month, up to 25% of the tax due, if the tax is not paid by the statutory due date. Failure mode: the team treats October 15, 2027 as the payment date. Fix: pay the estimate by March 15, 2027 and record the date paid.
How the federal Form 1120-S feeds the Georgia return
Finish the federal return first. Georgia uses the same entity figures and the Schedule K-1 amounts, and a complete copy of the federal return goes with it. If Form 600S is prepared from a draft 1120-S, any federal change means a second Georgia return. Lock the K-1 amounts first.
If an IRS audit changes taxable income, the booklet says the taxpayer must file a return reflecting the corrected net income “within 180 days of final determination,” as an amended Form 600S. Send the K-1 draft before the Form 600S-CA request.
Nonresident withholding: the rate and the $1,000 exception
The Department’s proposed amendment to Rule 560-7-8-.34 (Notice ITD-2026-001, dated January 23, 2026) says that “withholding is required at the rate of 4 percent” on each nonresident member’s share of Georgia-sourced income, “unless exempted by this regulation or O.C.G.A. 48-7-129.” The rule does not require withholding when a member’s aggregate annual share is less than $1,000.
Confirm the rate before you compute anything. I could not confirm from an official source whether this amendment was adopted as written, and I could not retrieve current text of O.C.G.A. 48-7-129. The copy I could reach is dated 2016 and also says 4 percent. The examples below use 4 percent. If the 2026 statute sets a different rate, scale every withholding figure to it.
Each nonresident member gets one of three treatments. The company can withhold. It can file a composite return on Form IT-CR, which “shall constitute the election” and must be made by the composite return’s due date, including extensions, if approved. Or it can make the irrevocable election to pay income tax at the entity level. Composite tax uses the individual rate under O.C.G.A. 48-7-20, so run that number before you pick composite.
Form 600S-CA: the certification and the decision rule
Form 600S-CA is the nonresident consent. Each nonresident shareholder agrees to pay Georgia tax on their share, either by filing Form 500 or by being included in a composite return on Form IT-CR. Attach a completed Form 600S-CA for each nonresident shareholder to Form 600S when it is filed, even if a composite return is filed. The copy I read is marked Rev. 7/13, so use the current Department version.
The deadline is strict. The member must certify in writing, on a one-time basis, “on or before the due date (without extension)” for the entity’s return. For tax year 2026 that is March 15, 2027, and the Georgia extension does not move it. If the member certifies and then fails the conditions, withholding is due as originally required.
Decision rule: if an owner certifies in writing by March 15, 2027, the company does not withhold on that share. If the owner does not certify, withhold on that share or elect composite for that owner. Send the request in writing, for example: “Please sign and return the enclosed Form 600S-CA by March 15, 2027. Without it the company must withhold on your Georgia share for tax year 2026.” Keep the signed copy in the file.
Worked example: one certification, two outcomes
Assume a Georgia S corporation with $500,000 of Georgia-sourced income for tax year 2026. Owner A is a Georgia resident with 40 percent. Owner B is a Florida resident with 40 percent. Owner C is a Florida resident with 20 percent. The nonresident share is 60 percent, or $300,000.
If neither nonresident owner certifies, the company withholds at 4 percent on the full $300,000, which is $12,000. If Owner C certifies by March 15, 2027, the company withholds on Owner B’s $200,000 only, which is $8,000. If Owner C certifies after March 15, 2027, that certification does not count, so Owner C’s $100,000 is withheld at 4 percent, which is $4,000. With Owner B’s $8,000 also withheld, the total is $12,000, the same as the no-certification case.
Failure modes and fixes
Failure: the team assumes the Georgia extension, but the federal Form 7004 was filed after March 15, 2027. Fix: check the IRS acceptance date against the original due date. A late Form 7004 does not give the seven months.
Failure: an owner under $1,000 is skipped entirely. Fix: the $1,000 test removes only the withholding duty. The booklet still requires Form 600S-CA for each nonresident shareholder, so test the share, record the result and attach the form.
Failure: a nonresident owner refuses to sign. The form says that if any nonresident shareholder fails or refuses to file the consent, “DO NOT USE FORM 600S.” Fix: stop and confirm the return with the Department before filing.