How to File W-2 Online: BSO Setup, Deadlines & Corrections

To file W-2 forms online, employers use the Social Security Administration’s free portal, Business Services Online (BSO). If you are submitting ten or more information returns of any kind for the year — W-2s and 1099s combined — federal rules require you to file electronically rather than on paper.1Internal Revenue Service. E-file Information Returns Below the threshold, BSO is still typically the fastest way to get wage reports filed and confirmed.

What to Have Ready Before You Log In

Gather the following for your business and every employee who received wages during the year:

  • Your Employer Identification Number (EIN). If you do not have one, you can apply free on the IRS website.2Internal Revenue Service. Employer Identification Number
  • Each employee’s full legal name and Social Security number, spelled exactly as they appear on the Social Security card. Name/SSN mismatches are one of the most common reasons filings get flagged.
  • Each employee’s current mailing address as of the end of the calendar year.
  • Wage and tax figures from your payroll records: gross wages and tips, federal income tax withheld, Social Security and Medicare wages, and state and local tax amounts.

Reconcile every dollar figure against your payroll system before you start entering data. If the totals on your W-2s do not tie to your quarterly Form 941 filings, expect an IRS notice.

Setting Up Your BSO Account

All electronic wage reporting runs through BSO, and the SSA no longer accepts its own standalone user ID for wage reporting. You now sign in with a Login.gov or ID.me credential.3Social Security Administration. BSO Tutorial Registration Services Registration asks for your first and last name, Social Security number, address, phone, email, and your EIN if the IRS has already issued one.4Social Security Administration. How to Register for BSO

Payroll services and other filers handling multiple businesses can register additional EINs under a single account. Set the account up well ahead of January, because identity verification can take extra time to resolve.

Filing the Forms

Once you are inside BSO, you have two paths. The fill-in method walks you through each box on the W-2 for one employee at a time and allows up to 50 forms per report. Larger employers upload a formatted data file that follows the SSA’s EFW2 specifications, which most payroll software produces automatically.5Social Security Administration. Specifications for Filing Forms W-2 and W-2c (EFW2/EFW2C) Either way, BSO generates and files the accompanying Form W-3 transmittal for you; you do not create a separate W-3.6Social Security Administration. Helpful Hints to Electronic Filing and Registration

The key boxes on each W-2:

  • Box 1, wages, tips, and other compensation: total taxable compensation for the year. This figure generally excludes pre-tax retirement contributions and certain elective deferrals.7Internal Revenue Service. General Instructions for Forms W-2 and W-3 (2026)
  • Box 2, federal income tax withheld from the employee’s paychecks.7Internal Revenue Service. General Instructions for Forms W-2 and W-3 (2026)
  • Boxes 3 through 6, Social Security and Medicare wages and taxes. These may differ from Box 1 because some income is subject to FICA even when it is exempt from federal income tax, and vice versa. The employee portion of Social Security tax is 6.2 percent on wages up to $184,500, and Medicare is 1.45 percent on all wages with no cap.8Internal Revenue Service. Topic No. 751, Social Security and Medicare Withholding Rates
  • Boxes 15 through 20, state and local wages and taxes. Each state sets its own rules for these fields.

Verify the employee’s name and SSN against their Social Security card on every form. Errors in these fields are the leading cause of processing delays and corrective filings.

Box 12 Codes

Box 12 uses letter codes for specific compensation and benefits. Common ones include Code D (401(k) elective deferrals), Code E (403(b) elective deferrals), Code G (457(b) contributions), Code AA (Roth 401(k) contributions), Code BB (Roth 403(b) contributions), Code DD (cost of employer-sponsored health coverage, not taxable), and Code W (employer HSA contributions).9Internal Revenue Service. 2026 General Instructions for Forms W-2 and W-3 Only four codes fit on a single W-2. If an employee has more than four, create an additional W-2 for that employee to carry the extras.

Testing an EFW2 File Before You Upload

If you are uploading rather than filling in forms, run the file through AccuWage Online first. This free SSA tool flags formatting problems at two levels: critical errors that would block processing entirely, and standard errors you have to fix before uploading to BSO.10Social Security Administration. AccuWage Online Help Guide AccuWage does not confirm that names match SSNs; that check happens after the SSA processes your submission. You cannot edit inside AccuWage either — fix issues in your payroll software, regenerate the file, and test again until it passes.

The Filing Deadline

Two deadlines apply, and they usually land on the same day. Employee copies must be furnished on or before January 31 of the year following the tax year.11Office of the Law Revision Counsel. 26 USC 6051 – Receipts for Employees Copy A of every W-2 must be filed with the SSA by that same January 31 (BSO transmits the W-3 for you). For tax year 2026, January 31 falls on a Sunday, so the deadline shifts to February 1, 2027.9Internal Revenue Service. 2026 General Instructions for Forms W-2 and W-3

There is no automatic extension for W-2s. If you need more time, mail Form 8809 to the IRS Service Center in Ogden, Utah, before the deadline, explain why, and sign the form. The IRS can grant only one 30-day extension, and approval is not guaranteed. Requests filed after the deadline are denied.12Internal Revenue Service. Form 8809 Application for Extension of Time to File Information Returns

After You Submit

BSO generates a confirmation receipt with a submission tracking number as soon as the SSA receives the report. Save or print it; that receipt is your proof of timely filing. The View Wage Report Status tool inside BSO shows whether the report was accepted or flagged for errors.

Federal recordkeeping rules require you to keep employment tax records, including your Copy D of each W-2, for at least four years after filing.13Internal Revenue Service. Employment Tax Recordkeeping

State Filing Is Separate

A BSO filing does not cover your state obligations. The SSA and IRS do not forward the state-level data from your electronic submission to state revenue agencies.14Social Security Administration. EFW2 Specifications File W-2s separately with each state where your employees work or reside, following that state’s own format, deadlines, and electronic filing rules.

Fixing Errors After You File

If you discover a misspelled name, wrong SSN, or wrong wage amount after submitting, file Form W-2c (Corrected Wage and Tax Statement) as soon as possible and give the corrected copy to the affected employee right away.15Social Security Administration. Helpful Hints to Forms W-2c/W-3c Filing BSO has a W-2c/W-3c Online section where you enter the previously reported amounts alongside the corrected amounts and submit. You can file up to 25 corrections per online submission, and BSO generates the W-3c transmittal automatically.16Social Security Administration. W-2c/W-3c Online Tutorial

If Electronic Filing Would Be a Hardship

If the cost of filing electronically would create an undue financial hardship — say you are a small employer without payroll software and lack reliable internet access — you can request a waiver from the electronic filing requirement by submitting Form 8508 to the IRS. Attach two current cost estimates from third parties comparing the expense of electronic filing to paper filing. Estimates from prior years or for unrelated services are not accepted, and omitting the two estimates results in automatic denial.17Internal Revenue Service. Form 8508 Application for a Waiver from Electronic Filing of Information Returns

Penalties for Late or Wrong Filings

The IRS charges separate penalties for failing to file correct W-2s with the SSA and for failing to furnish correct copies to employees. The amount rises the longer the error stands.7Internal Revenue Service. General Instructions for Forms W-2 and W-3 (2026)

  • Corrected within 30 days of the deadline: $60 per form, capped at $244,500 per year for small businesses.
  • Corrected after 30 days but by August 1: $130 per form, capped at $698,500 per year for small businesses.
  • Corrected after August 1 or not corrected: $340 per form, capped at $1,397,000 per year for small businesses.
  • Intentional disregard: at least $690 per form, with no maximum.

Because the SSA-filing penalty (IRC §6721) and the employee-copy penalty (IRC §6722) are separate, one missed form can draw two charges. Filing through BSO early enough to catch problems before January 31 is the practical way to keep them off your account.