Calculate bonus withholding

CBS offers two bonus calculators. Pick based on how you want supplemental wages withheld.

Percent (flat) method: `flatbonus`

Withholds using the supplemental flat rate. POST to flatbonus:

curl -X POST https://calculators.symmetry.com/api/calculators/flatbonus \
  -H "pcc-api-key: yourKey" -H "Content-Type: application/json" \
  -d '{"state":"CO","bonus":5000,"payFrequency":"WEEKLY","grossPayYTD":0,"federalFilingStatusType":"SINGLE","federalAllowances":0,"additionalFederalWithholding":0}'

The percent method is not available in every state. For states that don’t support it, the API returns HTTP 422 with a message like “CALIFORNIA does not support this type of calculation. Please select a different state.” See Handle states with no supplemental rate.

Aggregate method: `agbonus`

Combines the bonus with regular wages from the last paycheck to apply the correct withholding rates. POST to agbonus with the bonus plus the current pay context. Use this when the percent method isn’t available or isn’t appropriate.

Choosing

Percent/flat: simplest; a fixed supplemental rate on the bonus (where supported).
Aggregate: more accurate for the employee’s actual bracket; works in all states.

For which method each calculator uses, see Calculation methods by calculator.

⌘I

​Percent (flat) method: flatbonus

​Aggregate method: agbonus

​Choosing

Percent (flat) method: `flatbonus`

Aggregate method: `agbonus`

Choosing