Introduction: What Is IRS Form W-2GU?

IRS Form W-2GU, officially titled Guam Wage and Tax Statement, is a specialized territorial employment tax document published by the Internal Revenue Service (IRS). Governed jointly by the Department of the Treasury through the IRS, the Social Security Administration (SSA), and the Guam Department of Revenue and Taxation (DRT), this form is the territorial equivalent of the standard Form W-2.

Employers operating in the U.S. territory of Guam use Form W-2GU to report annual wages paid to employees and taxes withheld from those wages. Because Guam maintains its own localized income tax system while remaining fully integrated into federal social insurance programs, payroll reporting requires a dedicated form that accommodates both territorial and federal tax rules.

Form W-2GU serves a dual role: it provides the Guam Department of Revenue and Taxation with the income tax data necessary to process local tax returns, and it transmits wage records to the Social Security Administration so Guam workers receive full credit toward federal Social Security and Medicare benefits.

Purpose of the Form: Why Does Form W-2GU Exist?

Guam operates under a unique tax structure known as the “Mirror Code.” Under this system, the income tax laws of the United States are mirrored as the territorial income tax laws of Guam. Residents and workers in Guam pay income taxes directly to the Government of Guam rather than to the U.S. Department of the Treasury.

Despite this separate income tax destination, Guam employees are fully covered under the Federal Insurance Contributions Act (FICA). Just like workers in the 50 U.S. states, employees in Guam pay federal Social Security and Medicare taxes, which are matched dollar-for-dollar by their employers.

Form W-2GU solves the administrative challenge of reporting across two distinct tax jurisdictions. It documents local Guam territorial income tax withholding in Box 2, while tracking federal Social Security and Medicare wages in Boxes 3 through 6. This ensures that the Government of Guam collects its rightful income tax revenue while the federal government properly credits workers’ lifetime retirement accounts.

Who Needs to File Form W-2GU?

Form W-2GU involves annual reporting obligations for employers operating in Guam, as well as reporting duties for local employees:

Guam Employers: Any commercial business, partnership, corporation, nonprofit organization, or local government agency that pays wages or other compensation for services performed by an employee in Guam.
Employers Withholding FICA or Territorial Taxes: Any employer that withheld Guam income tax or federal Social Security and Medicare taxes, or would have withheld taxes if the employee claimed zero allowances.
Guam Employees: Workers do not fill out Form W-2GU themselves; they receive Copies B and C from their employers and use the reported figures to prepare their annual individual income tax return (Form 1040) filed with the Guam Department of Revenue and Taxation.

Who Is Exempt or Not Required to File?

Many businesses, workers, and entities operating outside Guam or outside traditional employment relationships do not use Form W-2GU:

Employers in the 50 States or Other Territories: Employers in mainland states file standard Form W-2. Employers in other U.S. territories use their dedicated forms: American Samoa uses Form W-2AS, the U.S. Virgin Islands uses Form W-2VI, and the Northern Mariana Islands uses Form W-2CM.
Independent Contractors and Freelancers: Independent contractors and non-employee service providers in Guam do not receive Form W-2GU; their income is reported on Form 1099-NEC or local territorial equivalents.
Sole Proprietors Without Employees: Self-employed individuals who take business draws rather than wage salaries do not receive a W-2GU. They report their earnings using Form 1040-SS or local tax schedules.
Unpaid Volunteers: Individuals who volunteer for religious or charitable groups and receive no taxable wages or taxable allowances are exempt.

When to File: Deadlines and Frequency

Form W-2GU is an annual filing with a strict universal deadline shared across all reporting agencies:

January 31 Distribution Deadline: Employers must furnish Copies B and C of Form W-2GU to their employees no later than January 31 of the year following the tax year.
January 31 SSA Filing Deadline: Employers must file Copy A, accompanied by transmittal Form W-3SS, with the Social Security Administration by January 31, whether filing electronically or on paper.
January 31 Guam DRT Deadline: Employers must also submit Copy 1 to the Guam Department of Revenue and Taxation by January 31.

If January 31 falls on a Saturday, Sunday, or legal holiday, the deadline shifts to the next business day.

Where and How to File Form W-2GU

Filing Form W-2GU requires distributing specific copies across federal, territorial, and employee channels:

Submitting Copy A to the Social Security Administration: Employers file Copy A, along with transmittal Form W-3SS, with the Social Security Administration. The SSA encourages electronic filing through its Business Services Online (BSO) portal. Employers filing 10 or more informational returns across all form types are legally required to file electronically.

Submitting Copy 1 to the Guam Department of Revenue and Taxation: Copy 1 must be filed directly with the Guam Department of Revenue and Taxation in Barrigada in accordance with local filing instructions.

Furnishing Copies B and C to Employees: Employers deliver Copy B (to be attached to the employee’s Guam tax return) and Copy C (for the employee’s personal files) in person or by mail. Secure electronic distribution is allowed only if the employee provides prior affirmative consent.

Paper Mailing Address: If permitted to submit paper forms to the SSA, employers mail Copy A and Form W-3SS to the official Social Security Administration address as per instructions (or the official IRS address as per instructions if directed in local tax guidance).

Step-by-Step Instructions to Fill Out Form W-2GU

Form W-2GU contains lettered boxes for employer and employee identifiers and numbered boxes for wage and tax amounts.

Box	Title / Field Description	Required Information & Operational Rule
Box a	Employee’s Social Security Number	Enter the employee’s nine-digit SSN exactly as shown on their official Social Security card.
Box b	Employer Identification Number (EIN)	Enter the employer’s nine-digit federal EIN assigned by the IRS (formatted as XX-XXXXXXX).
Box c	Employer’s Name, Address, & ZIP	Enter the legal business name and physical or mailing address in Guam.
Box d	Control Number	An optional internal payroll tracking number used by the employer.
Boxes e–f	Employee’s Legal Name & Address	Enter the employee’s legal first name, middle initial, last name, and current residential address.
Box 1	Wages, Tips, Other Compensation	Total gross taxable compensation subject to Guam territorial income tax.
Box 2	Guam Income Tax Withheld	Total Guam territorial income tax deducted from employee paychecks throughout the year.
Box 3	Social Security Wages	Total wages subject to federal Social Security tax, capped at the annual federal statutory limit.
Box 4	Social Security Tax Withheld	Total federal Social Security tax withheld (6.2% of Box 3).
Box 5	Medicare Wages and Tips	Total wages subject to federal Medicare tax (not subject to any annual ceiling).
Box 6	Medicare Tax Withheld	Total federal Medicare tax withheld (1.45% of Box 5, plus 0.9% Additional Medicare Tax if pay exceeds $200,000).
Boxes 7–8	Social Security & Allocated Tips	Report employee-reported tips subject to Social Security and any allocated tips.
Box 10	Dependent Care Benefits	Total pretax dependent care benefits provided under an employer assistance plan.
Box 11	Nonqualified Plans	Distributions made from a nonqualified deferred compensation plan.
Box 12	Coded Benefit Items	Enter standard IRS letter codes (e.g., Code D for 401(k) deferrals, Code W for HSA contributions).
Box 13	Checkboxes	Check if applicable: Statutory Employee, Retirement Plan participant, or Third-Party Sick Pay.
Box 14	Other Information	Used for optional or local employer reporting, such as local payroll deductions or union dues.

Understanding Key Boxes on Form W-2GU

Box 1 vs. Box 2: Guam Income Tax. On standard mainland W-2 forms, Box 2 reports federal income tax withheld. On Form W-2GU, Box 2 is strictly reserved for Guam income tax withheld. Box 1 reports the employee’s total wages subject to Guam’s mirrored tax rates.

Boxes 3 through 6: Federal FICA Taxes. Boxes 3 through 6 report federal Social Security and Medicare taxes. Box 3 captures Social Security wages up to the national annual wage base, while Box 5 captures all Medicare wages without a limit. These taxes are remitted to the federal government to fund the employee’s federal retirement benefits.

Box 12 Reporting Codes. Employers must use standard federal letter codes in Box 12. For example, elective employee deferrals to a 401(k) plan are entered under Code D, while employer-sponsored health coverage costs are reported under Code DD for informational tracking.

Required Documents and Information Needed Before Filling

Employers should gather the following payroll and identification records before completing Form W-2GU:

Employee Withholding Certificates: Completed withholding forms (Form W-4 or territorial equivalent) showing marital status, dependents, and withholding allowances.
Employee Identification Records: Verified Social Security cards and legal name records for all active personnel.
Annual Payroll Registers: Detailed summaries showing gross wages, pretax deductions, local Guam tax withholdings, and federal FICA withholdings.
Tax Identification Numbers: The business’s federal Employer Identification Number (EIN) and Guam Department of Revenue and Taxation employer account number.
Benefit Plan Statements: Year-end reports from retirement plan administrators and health insurance providers.

Common Mistakes to Avoid

Payroll errors on Form W-2GU can disrupt tax processing in both Guam and the mainland United States. Watch out for these frequent mistakes:

Using Standard Form W-2: Submitting a standard mainland Form W-2 instead of Form W-2GU causes severe errors, as automated IRS systems will mistakenly treat local Guam tax withholdings as U.S. federal income tax withholdings.
Failing to Submit Copy 1 to the Guam DRT: Sending Copy A to the SSA while forgetting to send Copy 1 to the Guam Department of Revenue and Taxation prevents local tax authorities from verifying employee tax returns.
Mismatched Employee Names and SSNs: Entering typographical errors in names or Social Security Numbers prevents the Social Security Administration from crediting earnings to the worker’s retirement record.
Missing the January 31 Filing Deadline: Late distribution to workers or late filing with government agencies triggers automatic statutory information return penalties.
Truncating SSNs on Copy A: While some employers truncate employee SSNs on employee copies for privacy, Copy A submitted to the SSA must always display the full nine-digit Social Security Number.

Penalties for Non-Filing or Errors

Failing to prepare and submit Form W-2GU accurately exposes employers to dual-jurisdiction penalties:

Federal Information Return Penalties (IRC Sections 6721 & 6722): The IRS assesses penalties for late, incomplete, or incorrect filings sent to the SSA or furnished to employees:
- Approximately $60 per form if corrected within 30 days.
- Approximately $130 per form if corrected between 31 days late and August 1.
- Approximately $330 per form if filed after August 1 or not filed at all.
- A minimum of $660 per form (with no maximum cap) for intentional disregard.
Guam Territorial Penalties: The Guam Department of Revenue and Taxation assesses separate local penalties and interest charges for failing to file Copy 1 or underreporting territorial wage withholdings.

Related Forms and Schedules

Form W-2GU operates within a broader system of territorial and federal tax forms:

Form W-3SS: Transmittal of Wage and Tax Statements (the summary transmittal sheet that must accompany paper Copy A filings to the SSA).
Form W-2c: Corrected Wage and Tax Statement (used to fix errors on previously filed W-2GU forms).
Form W-3c: Transmittal of Corrected Wage and Tax Statements.
Form 941-SS: Employer’s Quarterly Federal Tax Return for American Samoa, Guam, the Northern Mariana Islands, and the U.S. Virgin Islands (used to remit FICA taxes quarterly).
Form 1040-SS: U.S. Self-Employment Tax Return for residents of Guam and other territories.
Form W-2AS / Form W-2VI / Form W-2CM: Territorial wage statements for American Samoa, the U.S. Virgin Islands, and the Northern Mariana Islands.

Frequently Asked Questions (FAQs)

How does Form W-2GU differ from standard Form W-2?

Standard Form W-2 reports federal income tax withheld in Box 2 for workers in the 50 states. Form W-2GU is customized for Guam, reporting local Guam territorial income tax withheld in Box 2, while retaining standard federal reporting for Social Security and Medicare in Boxes 3 through 6.

Where do Guam residents file their individual income tax returns?

Bona fide residents of Guam file their Form 1040 directly with the Guam Department of Revenue and Taxation in Barrigada, not with the IRS in the mainland United States.

Do employees in Guam pay U.S. federal income tax on W-2GU wages?

Generally, no. Under the Mirror Code system, wages earned in Guam by bona fide residents are subject to Guam territorial income tax. However, workers remain fully subject to federal Social Security and Medicare taxes.

What transmittal form must accompany paper Form W-2GU filings?

When submitting paper copies to the Social Security Administration, employers must attach Form W-3SS, Transmittal of Wage and Tax Statements. Standard Form W-3 cannot be used for territorial filings.

Can employers in Guam file Form W-2GU electronically?

Yes. Employers can use the Social Security Administration’s free Business Services Online (BSO) portal to upload and submit Form W-2GU wage files electronically, satisfying federal filing requirements.

How does an employer correct an error on a filed Form W-2GU?

If an employer discovers an error after filing, they must prepare Form W-2c (Corrected Wage and Tax Statement), furnish copies to the employee, and submit Form W-2c along with transmittal Form W-3c to the Social Security Administration and the Guam Department of Revenue and Taxation.

Conclusion: Key Takeaways

IRS Form W-2GU, Guam Wage and Tax Statement, is an indispensable document for managing payroll in Guam. It balances local tax obligations under the Mirror Code with federal contributions to the Social Security and Medicare trust funds, ensuring that workers are taxed correctly and receive their rightful retirement credits.

For Guam employers, successful compliance requires separating local income tax withholdings from federal FICA deductions and meeting the mandatory January 31 deadline across all three key parties: employees, the Social Security Administration, and the Guam Department of Revenue and Taxation. Staying organized and filing accurately ensures smooth business operations and protects your workforce under territorial and federal tax law.

IRS Form W-2GU Guide: Guam Wage and Tax Statement Filing