Up to 12 of the closed stores could be converted to e-commerce facilities, the spokesperson said, with the first conversion already planned for a location in Memphis, Tennessee. The efforts come as the retailer is investing in its online capabilities.

That compares with a total of five wholesale club stores the company has closed since fiscal 2013, securities filings show.

Walmart is shuttering 63 of its Sam's Club locations across the U.S., with several stores closing their doors as early as Thursday, a company spokesperson told CNBC.

The company told CNBC all of Sam's Club's employees who are affected by the store closures will still be eligible for bonuses. It didn't disclose how many employees would be at risk of losing their jobs, but Sam's Club has said each of its stores has about 175 workers.

Reports of the Sam's Club closings began to emerge in local media outlets throughout Texas, New York, New Jersey Alaska and Arizona, amid complaints from disgruntled employees and confused customers. In some cases, employees weren't notified in advance, some of the publications said.

Sam's Club's Twitter account was issuing statements to upset customers by Thursday afternoon. Some people were asking to have their memberships refunded, among other complaints.

Tweet

When one user asked about picking up a prescription from a closing store, Sam's Club said, "Pharmacies will stay open for at least two weeks, and we will work with each state's Board of Pharmacy to help guide this transition."

Walmart issued a statement late Thursday saying it would book a charge of 14 cents per share related to the Sam's Club closures, which would show up mainly in its fourth-quarter results. The company said it would share more details when it reports earnings on Feb. 20.

Sam's Club has generally underperformed relative to Walmart, facing strong competition from discount peer Costco, which has excelled at merchandising and vendor relations, and online wholesale retailer Boxed. In recent years, Walmart has focused on reviving the brand.

At an October meeting with investors, Sam's Club CEO John Furner said the retailer needed to improve its "competitive position" as same-store sales growth started to stall into the first half of fiscal 2018.

Those efforts would include better targeting households that make between $75,000 to $125,000, Furner said. At the time, he didn't speak to whether Sam's Club would be closing or opening more stores as part of achieving those goals.

More broadly, Walmart has been investing in its digital business, underlined by its change of name from Wal-Mart Stores to Walmart. These efforts have been propelled by its acquisition of Amazon competitor Jet.com, through which it has been building a coterie of online brands.

After the closures are complete, Walmart will operate 597 club stores across the country.

Here is a list of the stores being closed:





8801 Old Seward Hwy, Anchorage, AK

1074 N Muldoon Rd, Anchorage, AK

48 College Rd, Fairbanks, AK

3900 Grants Mill Rd, Irondale, AL

2425 E Florence Blvd, Casa Grande, AZ

5757 E State Route 69, Prescott Valley, AZ

1375 S Arizona Ave, Chandler, AZ

15255 N Northsight Blvd, Scottsdale, AZ

3360 El Camino Ave, Sacramento, CA

17835 Gale Ave, City of Industry, CA

12540 Beach Blvd, Stanton, CA

12920 Foothill Blvd, Sylmar, CA

69 Pavilions Dr, Manchester, CT

2 Boston Post Rd, Orange, CT

355 FL-436, Fern Park, FL

7233 N Seacrest Blvd, Lantana, FL

5135 S Dale Mabry Hwy, Tampa, FL

2994 Turner Hill Rd, Lithonia, GA

501 N Randall Rd, Batavia, IL

21430 S Cicero Ave, Matteson, IL

6600 44th Ave, Moline, IL

808 S Illinois Rte 59, Naperville, IL

900 S Barrington Rd, Streamwood, IL

1055 McHenry Rd, Wheeling, IL

460 S Weber Rd, Romeoville, IL

3015 W 86th St, Indianapolis, IN

10859 E Washington St, Indianapolis, IN

4024 Elkhart Rd #1, Goshen, IN

9598 Cortana Pl, Baton Rouge, LA

9750 Reisterstown Rd, Owings Mills, MD

1 Tobias Boland Way, Worcester, MA

340 E. Edgewood Boulevard, Lansing, MI

32625 Northwestern Hwy, Farmington Hills, MI

3745 Louisiana Ave S, St Louis Park, MN

2800 27th Ave S, Moorhead, MN

11 Batchelder Rd, Seabrook, NH

81 International Dr S, Budd Lake, NJ

1900 E Linden Ave, Linden, NJ

301 Nassau Park Boulevard, Princeton, NJ

2649 Erie Blvd E, Syracuse, NY

720 Fairmount Ave, Jamestown, NY

700 Elmridge Center Dr, Rochester, NY

1600 Marketplace Dr, Rochester, NY

5085 Dawn Dr, Lumberton, NC

1101 Shiloh Glenn Dr, Morrisville, NC

4825 Marburg Ave, Cincinnati, OH

9570 Fields Ertel Rd, Loveland, OH

615 Old Hickory Blvd, Nashville, TN

1805 Getwell Rd, Memphis, TN

1615 S Loop W, Houston, TX

13331 Westheimer Rd, Houston, TX

22296 Market Place Dr, New Caney, TX

12919 San Pedro Ave, San Antonio, TX

741 E Little Creek Rd, Norfolk, VA

4571 S Laburnum Ave, Richmond, VA

901 S Grady Way, Renton, WA

1101 Outlet Collection Way, Auburn, WA

13550 Aurora Ave N, Seattle, WA

7050 Watts Rd, Madison, WI

1540 S 108th St, West Allis, WI

This list does not contain three additional stores in Puerto Rico.

— CNBC's Courtney Reagan contributed to this story.