Map Payroll Export Fields to an EFW2 File

Identify the payroll product, export version, tax year and employer reporting population. A column named taxable_wages is not enough: determine whether it represents federal income tax wages, Social Security wages, Medicare wages or a state amount. Record the business definition next to the technical column name.

The 2026 EFW2 specification includes layout changes. Keep the SSA publication date in the mapping document and inspect the annual change list before carrying a previous mapping forward. The record type and position together identify a destination; position 188 means different things in RW and RO. Make that pair explicit in every mapping row.

Use distinct input groups for submitter information, employer information and employee values. Submitter identity belongs in RA; it does not replace the reporting employer's EIN in RE. The employee's reporting identity and monetary amounts belong in the appropriate employee records.

Some outputs require a decision rather than a direct copy: employment code, tax jurisdiction, retirement plan indicator or an applicable Box 12 code. Identify who owns that decision and the payroll evidence behind it. Do not derive a retirement indicator merely from an employee's age or job title. Define what happens when an input is absent, duplicated or inconsistent. A rejected mapping row is easier to investigate than an invented default that looks valid.

The following fictional example covers three fields in a domestic RW record under the 2026 specification. It is a mapping excerpt, not a full payroll tax calculation. All other required fields and record controls still need their own mappings.

Check these destinations against Section 4 and the W-2 box cross-reference in SSA's EFW2 publication. For territory reporting, follow the relevant jurisdiction rules rather than applying this domestic example unchanged. Keep the original display value in a restricted review extract so the transformation can be reconstructed.

Represent money in integer cents or an exact decimal type. Define rounding at the approved payroll calculation boundary, then format an eleven-position employee money field using implied cents, right justification and zero fill where specified. Do not truncate an amount that exceeds its field or accept a negative sign in a nonnegative field.

Keep SSNs, EINs and postal codes as strings so leading zeros survive. For names and addresses, document permitted characters, padding and length handling. Escalate an overlong value instead of silently removing identity information. Test a value exactly at the field width, one character beyond it, an empty value and a value containing a non-ASCII character. These cases expose assumptions ordinary employee examples miss.

RO is called optional, but it is required when an RO field applies to an employee. For 2026, SSA adds separate fields for certain tip taxes, additional existing Box 12 codes and new codes including TP and TT. Consult both the SSA layout and the 2026 W-2 instructions before deciding which source amounts belong there.

Do not treat all overtime earnings as qualified overtime compensation, or all payroll tip columns as the same reporting measure. The payroll tax interpretation must precede the field conversion. Add a mapping row for the associated total record whenever adding an employee money field. Otherwise employee detail can be correct while employer controls omit the new category.

Build a small fictional test set covering ordinary wages, multiple applicable codes, leading-zero identifiers and separate employers. Compare generated record excerpts with the mapping specification. Recompute employer totals from emitted employee values and compare them with an independently approved payroll summary.

Run AccuWage Online on the generated file, then save the mapping edition, source sample, output and test result together. A format pass cannot establish that taxable_wages was the right payroll column. Require a reviewer who understands the payroll definitions to check the field choices. When a payroll vendor changes its export, repeat the relevant mapping review before processing the next live release.