Next is cutting sick pay for unvaccinated workers who must isolate after being exposed to Covid.
The retail giant said it was an "emotive topic" but had decided to dock pay to protect the needs of its staff and shareholders after experiencing higher than expected absences for this time of year.
Next workers who have not had the vaccine but test positive for the virus will continue to receive their sick pay in full, however.
People who have been vaccinated no longer have to isolate if they have been exposed to a positive case, but anyone who has not been jabbed must still self-isolate for 10 days after exposure.
The retailer pays its store sales staff between £6.55 and £9.21 an hour. Warehouse workers receive an hourly wage of between £9.30 to £11.26.
Those who are unvaccinated but self-isolating will be handed the statutory minimum sick pay of £96.35 a week, according to reports.
The move comes as companies grapple with significant workforce absences due to covid sickness or self-isolation following the spread of the omicron variant, which has proven to be more infectious than previous strains.
Next is following in the footsteps of Ikea, the Swedish furniture retailer, that announced plans on Monday to reduce sick pay for unvaccinated staff who are self-isolating.
Ikea said it was a "highly emotive topic" and planned to assess each instance on a "case-by-case basis".
Next's move comes just a week after revealing it was on course for record profits after festive season sales jumped by a fifth.
Pre-tax profits are poised to reach £822m for the year to January, up from previous forecasts of £813m and significantly higher than the £670m forecast at the beginning of the period.