ISSAQUAH, Wash. — Costco Wholesale Corp. posted a 12.5% increase in net sales for its fiscal 2020 fourth quarter, which ended on August 30.

Net sales for the quarter totaled $52.28 billion for the 16-week quarter, up from $46.45 billion in the comparable period last year. Net sales for the fiscal year increased 9.3%, to $163.22 billion, up from $149.35 billion last year.

Comparable sales increased 13.6%, adjusted, in the U.S. for the quarter and 9.2% for the year. For the company as a whole, the adjusted comparable sales gain was 9.2% for both its U.S. operations and for the total company.

Net income for the fourth quarter was $1.389 billion, or $3.13 per diluted share, compared to $1.097 billion, or $2.47 per diluted share last year. This year’s fourth quarter was negatively impacted by incremental expense related to COVID-19 premium wages and sanitation costs of $281 million pretax ($0.47 per diluted share) and a $36 million pretax charge ($0.06 per diluted share) related to the prepayment of $1.5 billion of debt. These items were partially offset by an $84 million pretax benefit ($0.15 per diluted share) for the partial reversal of a reserve of $123 million pretax ($0.22 cents per diluted share), related to a product tax assessment taken in the fourth quarter of last year.

Net income for the fiscal year was $4.00 billion, or $9.02 per diluted share, compared to $3.66 billion, or $8.26 per diluted share in the prior year.

Costco finished the quarter and the fiscal year with 795 warehouse clubs, including 552 in the United States and Puerto Rico, 101 in Canada, 39 in Mexico, 29 in the United Kingdom, 27 in Japan, 16 in Korea, 13 in Taiwan, 12 in Australia, three in Spain, and one each in Iceland, France, and China. Costco also operates e-commerce sites in the U.S., Canada, the United Kingdom, Mexico, Korea, Taiwan, Japan, and Australia.