IRS W-4 Lock-In Letters: An Oregon Employer Checklist

Quick answer: follow the notice, not a replacement W-4

If the IRS sends your business a withholding lock-in letter, use the permitted filing status and withholding instructions on the date the notice specifies. After the IRS issues the notice, an employee cannot use a new Form W-4 to reduce federal withholding without IRS authorization. You must honor a valid new W-4 that produces more withholding.

This is an existing federal payroll process, not a new Oregon law. For a Bend shop, Redmond contractor or other Oregon employer, the practical job is to route the notice to payroll, schedule implementation and prevent employee self-service settings from undoing it. Keep Oregon withholding as a separate review.

Read the actual letter before changing payroll

The IRS uses reported wage information to identify withholding problems and may send an employer a lock-in notice for a specific employee. Publication 15, section 9, describes permitted filing status and withholding instructions. Do not apply a generic online example to every employee or automatically translate an older notice into current W-4 fields.

Record the letter date, receipt date, employee identity, instructions and effective date. IRS withholding-compliance questions and answers say initial implementation is no sooner than 60 calendar days after the letter date. Publication 15 says not to implement the initial notice immediately on receipt. Use the actual notice’s date and instructions, with your provider’s help if the payroll fields are unclear.

Publication 15 also requires you to furnish the employee copy within 10 business days of receipt when the employee is employed by you as of the notice date. Treat delivery and payroll implementation as separate tasks. Save evidence of delivery without sharing the employee’s tax information with managers who do not need it.

Protect the setting without blocking legitimate increases

Set a restricted payroll flag for the employee and identify who can approve changes. IRS guidance requires you to block online W-4 changes that would decrease withholding after lock-in. A portal that accepts a form without enforcing that restriction can leave the employer using the wrong settings.

Compare the withholding produced by a proposed W-4 with the notice-based calculation. A form with different boxes checked does not, by itself, prove that withholding increases. Ask your provider to review the result using the applicable tax tables, pay period and wage assumptions. Keep the comparison with the change record.

If the employee’s completed W-4 produces more withholding, honor it. If it produces less, or claims complete exemption, follow the IRS notice unless the IRS authorizes the change. The employee must contact the IRS about a reduction; a manager’s approval or an employee’s assurance does not replace that authorization.

Worked example: compare results for the same paycheck

Suppose your provider calculates $220 of federal income tax withholding under the lock-in instructions and $180 under a proposed W-4 for the same paycheck. These are hypothetical calculation outputs, not a tax-table example or prescribed rates. The proposed form reduces withholding by $40, so payroll must keep the notice-based result unless the IRS authorizes the reduction.

Repeating that $40 reduction on three otherwise identical checks would leave $120 less federal tax withheld. IRS questions and answers warn that an employer that fails to follow lock-in instructions is liable for the additional tax that should have been withheld. Avoid a second error: do not treat this illustration as permission to recover missed tax from a later paycheck without reviewing the facts and applicable rules.

If a different valid W-4 produces $250 on the same paycheck, it increases withholding by $30 over the $220 notice-based amount and must be honored. Neither comparison determines the employee’s final annual tax liability. Your payroll calculation implements withholding instructions; it is not personal tax advice.

Plan for leave, termination and a return to work

An inactive payroll status does not settle the notice’s treatment. Publication 15 describes employees not currently performing services, including cases involving later wages for prior services, an expected return within 12 months of the notice, or certain leaves and reemployment rights. Review the specific condition instead of assuming every inactive employee falls outside the process.

Where the notice’s duties apply and employment ends after the notice date, Publication 15 requires continued notice-based withholding on wages still subject to federal income tax withholding. It also requires notice-based withholding if the employee resumes employment within 12 months after termination. Keep the notice flag in the rehire workflow so a new onboarding form does not erase it.

Handle an IRS modification without restarting the waiting period

The IRS can send a subsequent modification notice changing the permitted filing status or instructions. Publication 15 says to follow its specified effective date. The IRS questions and answers state that Letter 2808C modifications take effect immediately on receipt, rather than after another 60-day wait. Read the actual notice and escalate any unclear or conflicting instruction before making assumptions.

Do not remove a lock-in because a calendar year ended, payroll software changed, or the employee says a tax return has been filed. Retain the controlling IRS instruction until an authorized modification or release changes it. Ask your payroll provider to preserve the notice and restriction when migrating employee records.

Keep Oregon withholding separate

The IRS lock-in concerns federal income tax withholding. Oregon DOR’s 2026 OR-W-4 instructions explain that the redesigned federal W-4 cannot serve all Oregon withholding purposes and employees must use Form OR-W-4 instead. Check the state certificate and settings separately rather than copying federal lock-in fields into Oregon payroll.

An unchanged Oregon certificate does not necessarily guarantee an unchanged Oregon withholding result: Oregon’s calculation has its own inputs. Have your provider review the federal and state calculations together, using current Oregon instructions, while preserving the distinction between the IRS notice and the state certificate.

Use this employer action checklist

Assign one payroll contact to own the notice and one reviewer to verify implementation. Publication 15’s general employment-tax recordkeeping rule requires records for at least four years. Keep relevant withholding certificates and the implementation record with restricted access, and ask your adviser whether your circumstances require longer retention.

• Log the letter and receipt dates, employee identity, exact instructions and effective date.
• Deliver the employee copy on time and preserve evidence of delivery.
• Schedule the notice-based calculation and verify the first affected payroll with your provider.
• Restrict online decreases while retaining a review path for valid requests that increase withholding.
• Carry the notice flag through leave, rehire and payroll-system changes.
• Retain later IRS modifications or releases and verify their implementation dates.

Common mistakes and practical payroll help

Common mistakes include implementing the initial notice on receipt instead of its specified date, overlooking the employee-copy deadline, accepting a lower-withholding W-4, and restarting a 60-day wait for a modification. Treat a contested tax position as a matter for the employee and IRS, not a payroll manager’s personal judgment.

Bend Payroll & Insurance can help Oregon small employers organize payroll settings, change reviews and notice handoffs. Use the payroll-services and HR-support pages linked with the sources to discuss your process with Joy. Ask about the existing first-month-free payroll offer and schedule a free payroll consultation; the service does not promise a particular tax outcome.

Joy Bunde, SHRM-CP, is a payroll and HR professional, not an attorney or CPA. This article provides general educational information, not legal or tax advice. Follow your actual IRS notice, verify current agency instructions and consult the IRS or a qualified legal or tax adviser about your circumstances.

Frequently asked questions