My employer called it redundancy but I think it was dismissal

Redundancy has a specific legal definition under the Employment Rights Act 1996: it occurs when an employer ceases or intends to cease carrying on the business, closes a workplace, or the requirements for employees to carry out work of a particular kind have diminished or ceased.

A "sham redundancy" arises when an employer uses the label of redundancy to remove an employee they want to dismiss for other reasons — for example, performance issues, a personal conflict, or whistleblowing. The individual is selected not because the role is genuinely redundant but for a reason specific to them.

Indicators of a sham redundancy include: the role being subsequently filled by another person; a genuine reduction in headcount not occurring; the selection appearing targeted at a specific individual; the absence of a proper selection pool; failure to follow a genuine selection and consultation process; and the timing coinciding with a grievance, whistleblowing report, or exercise of a legal right.

To challenge this in the Employment Tribunal, you would claim unfair dismissal (requiring two years' service) or automatically unfair dismissal (no qualifying period) if the real reason falls within a protected category such as whistleblowing or discrimination.

It is important to gather evidence of the company's recruitment activity after your redundancy (LinkedIn, job boards, Companies House filings), any communications suggesting performance concerns or personal issues pre-redundancy, and any procedural failures in the process.

Seek advice promptly — the three-month time limit applies from your last day of employment.