Canada's postal workers could walk off the job or the company could lock them out as soon as 12:01 a.m. ET Friday if the union and the company don't reach an agreement. Here are tips for shoppers and businesses.

The Canadian Union of Postal Workers has given 72-hour strike notice to Canada Post. The notice is for both the union's urban bargaining unit and its rural and suburban unit. In a release early Tuesday morning, the union says workers will be in a legal strike position as of Friday if negotiated settlements have not been reached.

Postal workers across the country could be off the job starting Friday if there’s no breakthrough in contract negotiations with Canada Post — a disruption that would come just ahead of the busy Christmas holiday season.