If you are dismissed and the sole or principal reason is a TUPE transfer itself, the dismissal is automatically unfair (with 2+ years' service). However, redundancies can be lawful where there is a genuine economic, technical or organisational (ETO) reason entailing changes in the workforce — such as genuinely duplicated roles after a merger.
Your continuous service transferred with you, so redundancy pay must include your years with the old employer. A full fair process still applies: genuine consultation, objective selection criteria, and consideration of alternative roles. Strict time limits apply — ACAS Early Conciliation must start within 3 months less one day of dismissal.
Check your entitlement with the redundancy pay calculator and test the process with the redundancy legality checker.