Sources suggest that you can safely store homemade haggis in the refrigerator for two days and up to a month in the freezer.
Manufacturers give store-bought haggis a refrigerator life of 2-4 weeks from the dispatch date as long as it remains unopened. Once prepared, you shouldn't keep it in your refrigerator for longer than two days. Haggis may be kept frozen for 6 to 12 months.
Homemade haggis should be cooked within 2 days of defrosting and store-bought haggis should be cooked within 2 weeks of defrosting.
Your refrigerator temperature should be set at 5ºC or below and your freezer temperature should be kept at -18°C or below to prevent the growth of dangerous bacteria like listeria.