All five Costco stores in Ottawa will be able to start selling beer and wine today, as Ontario expands alcohol sales to more grocery stores across the province. As of Oct. 31, all eligible grocery and big-box stores are able to buy beer, cider, wine and ready-to-drink beverages, including large pack sizes. The Ontario government says an additional 400 grocery stores will be selling alcohol across the province. "This is a big move. This is 100 years of a monopoly system we're opening up, catching up with the rest of the world," Finance Minister Peter Bethlenfalvy told reporters on Tuesday. This is the final step in Ontario's expansion of alcohol sales, after convenience stores were allowed to start selling beer cider, wine and ready-to-drink alcoholic beverages in September. On Aug. 1, previously licensed grocery stores were allowed to sell ready-to-drink beverages and large-pack sizes of beer. In Ottawa, five Costco stores and four Walmart stores have approval to sell alcohol after receiving a licence from the Alcohol and Gaming Commission of Ontario. Several independent grocery stores will also be eligible to now sell alcohol. More than 180 gas stations and convenience stores in Ottawa are licensed to sell alcoholic beverages. “We promised to give the people of Ontario choice and convenience when buying and selling alcoholic beverages and with today’s expansion, we got it done,” Premier Doug Ford said in a media release on Thursday. “This last phase of expansion will create new opportunities for retailers of all sizes and for Ontario producers of beer, wine, cider and ready-to-drink beverages. I hope everyone gets the chance to pick up one of these fantastic Ontario-made products and enjoy responsibly!” The Ontario government says approximately 4,700 convenience stores and 850 grocery stores, including big box retailers, are licensed to sell beer, cider, wine and ready-to-drink beverages across Ontario. Here are the rules for grocery stores and big box retailers to sell alcohol: The AGCO notes there are restrictions on single containers, meaning big box retailers can't sell anymore more than any other convenience or grocery store. The licence obligation guide notes a single container of beer, wine, or ready-to-drink beverages must not be bigger than 5 litres and cannot exceed 18 per cent alcohol. Here is the list of the grocery stores and big-box stores permitted to sell alcohol as of Oct. 31: The Ontario government has launched an interactive map to allow residents to search for retailers. With files from CTV News Toronto's Phil Tsekouras