Table service returned to bars and restaurants in North from last month
The change is happening at midday following a decision by Stormont ministers last week.
Nightclubs – which were forced to close on 26 December – will also reopen later, along with the return of indoor standing events.
Vaccine passports will still be required to access nightclubs and large events.
The Stormont Executive said the use of Covid certification in hospitality would continue to be “strongly encouraged”, but in guidance only.
The latest relaxation of Covid rules was approved by the executive after health officials advised that the North of Ireland had passed the peak of community transmission with the Omicron variant.
From Wednesday, the legal requirement for offices to take reasonable measures for 2m (6ft) social distancing is being removed, with guidance remaining in place that risk assessments should be carried out.
However, further advice remains that people should work from home where they can and take lateral flow tests before meeting others.
The executive will meet again on 10 February to review the remaining Covid restrictions in Northern Ireland.
This will include the laws on mandatory use of face coverings, the legal requirement for track-and-trace in hospitality and the use of Covid certification in nightclubs and for large events.
Nightclubs have been preparing to reopen since hearing of the relaxation in regulations.
On Friday, First Minister Paul Givan said it was his “continued view” that vaccine passports should be scrapped in all settings.
It came after the Irish government decided to end the use of Covid certification for all but international travel in the Republic of Ireland on Saturday.
