How to Migrate From Your Current HR System
The fear of migration is one of the most common reasons organisations stay with an HR system they know is not working. The data transfer seems risky. The possibility of losing historical records creates anxiety. The prospect of re-entering employee information that already exists somewhere is unappealing. These fears are understandable but typically overstated: a well-planned migration is less disruptive than the ongoing cost of working with a system that is not meeting the organisation's needs.
The starting point is a data audit: what do you actually have in the current system, and how much of it needs to move to the new one? Most organisations, when they audit their current HR data, find that it is less complete and less structured than they assumed. Employee records that are missing fields. Leave histories that are inconsistent because different managers have been tracking differently. Pay records that exist in one system and payroll data in another that have never been reconciled. The data audit surfaces these gaps before migration — when they can be addressed as part of the migration process — rather than after.
The data that is essential to migrate is narrower than it seems: active employee records (personal information, employment start date, current role and salary, current leave balance), current open HR cases, and document records for employees where the documents remain relevant (current contracts, signed policies). Historical records — past leave transactions, old performance ratings, archived documents from employees who have left — can typically be archived rather than migrated, reducing the migration scope significantly.
The migration sequence should be planned before any data is moved. Typically: export from the current system in the format the new system accepts; clean and validate the data (resolve duplicate records, fill mandatory fields, correct obvious errors); import into the new system in a test environment; validate the test import (does the employee count match? are balances correct? are documents attached correctly?); go live with the validated data; and decommission the old system access on a planned date. Trying to migrate in a single step without a test environment is the most common migration failure mode.
The most common data migration challenge in HR is leave balance accuracy. Year-to-date leave usage and current entitlement data must be accurate at the point of migration, because employees will immediately check their balances in the new system and raise queries if they appear wrong. Extracting leave data from the current system, validating it against manager records and recent payslips, and importing it with a clear cutoff date, reduces the post-migration query volume that would otherwise occupy HR team time.
The cut-over timing matters. Migrating at the start of a leave year, or at the start of a payroll period, minimises the complexity of partial-year calculations. Migrating mid-year with part-year balances, mid-period payroll configurations, and ongoing HR cases requires more careful data handling but is entirely manageable with good preparation. The worst cut-over timing is immediately before a major payroll run or a period of high HR activity.
Mellow's data import tools are designed for migrations from the most common HR platforms and spreadsheet formats, with validation checks that flag common issues before the import is completed. The migration support team provides guidance on the migration sequence and is available to review data files before import to identify issues that would otherwise require correction after go-live.