Anyone who refuses to wear one will face fines of up to €2,500 and time in prison.
The rule will not apply to children under 13 or anyone who can't wear one due to physical or mental incapacity.
Retail staff will be required to wear one unless there's a partition or space of two metres between them and customers.
Duncan Smith from Retail Excellence says retailers have the power to call Gardaí over non compliance - but don't expect they'll have to:
