Data Migration Checklist: Proven Guide to Avoid Costly Errors
A data migration checklist is the least glamorous document in a system replacement and the one that decides whether the project lands on the planned weekend or drags into a six-month cleanup. Extracting records from one database and loading them into another is the solved part; proving that what arrived is the same as what left, in a form the business will sign, with a credible way back if it is not, is where migrations are won and lost. This guide sets out a working checklist for UK businesses: what to profile before writing a single mapping, the four validation layers and the defects each one catches, how to build a reconciliation pack finance will actually sign, how to design and time a rollback you could execute at 3am, cutover sequencing, UK GDPR duties, realistic cost and timeline bands, and the failure modes each checklist item exists to prevent.
