Parallelproof

Parallel payroll runs are a well-established migration practice, but the supplied research says they are commonly handled through spreadsheets or vendor implementation teams rather than standalone software. It found no reviewed product automating employee and pay-code comparison across two live payroll systems. The technical diff is straightforward; the product value is controlled mapping, specialist disposition and rerun evidence.

Parallelproof would preserve organization, migration, pay period, old source, new source, extraction time, source run identifier, employee-key mapping, pay-code mapping, currency, earning line, deduction line, tax line, garnishment line, benefit line, net pay, rounding rule, source total, normalized value, variance, threshold, expected variance, unknown variance, payroll-specialist finding, root-cause assertion, correction request, source-system readback, rerun, approval scope, unresolved exception, cutover recommendation, cutover decision, signer and signature result as distinct records.

Matching systems can both be wrong. Different pay codes can be equivalent, while identical labels can carry different tax or accounting meaning. A threshold can hide small but harmful employee-level differences. A signed sign-off supports integrity and approval evidence but does not prove correct pay, tax, garnishment, benefits, source completeness, legal compliance or a safe cutover. A named payroll owner decides whether exceptions are acceptable and whether to switch.

The pilot should use synthetic or de-identified historical runs with no live payroll or employee actions. No model may correct source data, approve variances, submit payroll or authorize cutover. The buyer is a payroll transformation, implementation, HR operations or finance owner, often working with a consultancy or provider. Migration volume, supported systems, data access, mapping effort, jurisdiction, budget and willingness to buy a standalone product remain unverified. Numeric connection costs are omitted as market references.

A payroll transformation, implementation, HR operations or finance owner responsible for evidence-backed parallel-run review before migration.