S.I. 21 of 2021, which included credit unions, banks and post offices in the list of businesses and premises to which the Instrument now applies.
S.I. 296 of 2020 outlines, in detail, the definitions, the specific circumstances in which face coverings must be worn, reasonable excuses for their non-use and the obligation for reasonable persons (credit unions) to promote compliance with these legal requirements.
Please read both Statutory Instruments in tandem for a complete understanding of this issue.