Determination engine

Which state do you actually withhold in?

Reciprocity, convenience-of-the-employer, nonresident thresholds and unemployment localization, applied together to one employee's facts. Every answer cites the state source it came from.

Withhold Colorado income tax.

Wyoming residents get no exemption from Colorado tax, so the work state governs.

Income tax withheld to

Colorado

Flat 4.4%

Employee certificate

DR 0004

Colorado Employee Withholding Certificate

Unemployment insurance

Colorado

Localized under factor 1: Localization.

Reciprocal agreement

Colorado has no reciprocal agreements.

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Withhold Colorado nonresident income tax

Colorado taxes wages earned inside the state by nonresidents, and no reciprocal agreement covers Wyoming residents. Colorado requires withholding from the first dollar of in-state wages.

Colorado has local income taxes

Several Colorado cities (Denver, Aurora, Glendale, Greenwood Village, Sheridan) impose an Occupational Privilege Tax -- a flat monthly per-employee 'head tax' with both an employee-withheld portion and an employer portion. It is not an income-based tax. Colorado also has the state-run FAMLI paid leave premium.

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Colorado paid family and medical leave contributions

Colorado FAMLI 2026 premium is 0.88% of wages up to the Social Security wage base ($184,500), split 50/50: 0.44% employee, 0.44% employer. Employers with fewer than 10 employees owe no employer share but must still withhold the employee 0.44%. Employee contribution: 0.44%. These follow the state of unemployment coverage, not the income tax state.

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Employer registrations you will need

Colorado — Income tax withholding: Colorado Department of Revenue
Colorado — Unemployment insurance: Colorado Department of Labor and Employment (CDLE)

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Get the form

DR 0004 — Colorado (official state source)

Colorado profile Wyoming profile Full write-up for this pair

Change the inputs

Withholding determination

Answer six questions. The result is a shareable link, so you can paste it into a ticket or an email.

Employee lives inState of residence

Work is performed inWhere the employee physically sits

Employer is based inWhere the work is directed from

Days in the work stateThis calendar year, leave blank if unknown

Wages from work-state daysUS dollars, leave blank if unknown

Arrangement Works remotely rather than at an employer location Remote work is an employer necessity, not employee preference

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This is a determination aid, not advice. StateSide encodes published state rules and applies them mechanically to the facts you enter. It does not know your entity structure, your nexus history, your equity compensation, or the dozens of exceptions that turn a clean rule into a judgement call. Every determination cites the state source it came from — verify against that source, and take anything consequential to a payroll tax professional before you act on it.