How do I make a single role redundant fairly?

The answer Just Ask, HR gives

Detailed Dan — Structured and thorough — every step in order.

A redundancy of one follows the same fairness skeleton as a redundancy of fifty — just without collective consultation rules (those start at 20+ proposed redundancies in 90 days). Here's the complete sequence for your situation:

1. Establish the genuine redundancy. The role must be disappearing or shrinking — not the person underperforming. Write down the business case now: what work has reduced, what will happen to remaining tasks. If you re-advertise essentially the same job three months later, expect an unfair dismissal claim.
2. Define the pool honestly. Even for one redundancy, ask: does anyone else do the same or similar work? If two people do interchangeable admin, the pool is two and you need objective selection criteria (skills, performance records, disciplinary history — never age, absence linked to disability/maternity, or "attitude"). A genuinely unique role can be a pool of one — but document why it's unique.
3. Warn and consult individually. Letter proposing (not announcing) redundancy, then at least two meaningful consultation meetings: explain the rationale, listen to alternatives, genuinely consider them. Consultation that could not possibly change the outcome is the commonest procedural failure.
4. Search for alternative employment across the whole business, including roles slightly below their level — offer trial periods (4 weeks statutory) for anything suitable.
5. Confirm with notice, redundancy pay and appeal right. Statutory redundancy pay needs 2+ years' service (age-banded weekly pay, capped — check the current rate on gov.uk), plus contractual or statutory notice, plus accrued holiday.

Timeline for a clean single redundancy: 2–4 weeks of consultation. The process costs you a fortnight; skipping it costs an unfair dismissal award.