NEW YORK, United States — Gap Inc. is expanding its service that allows shoppers to reserve items online and then pay for and pick up the merchandise at the store within 24 hours.

The retailer began testing the option in 40 Gap and Banana Republic stores in Chicago and San Francisco in June. It differs from most other store pickup programs in that shoppers don't have to pay until they get to the store.

Starting this week, its entire fleet of U.S. Banana Republic stores, which number more than 400, will offer the service. It's also rolling out the strategy to more than 200 of its 700-plus namesake stores in 15 major U.S. markets. The company doesn't have definite plans for its Old Navy U.S. division, which has more than 900 locations.

As part of the service, shoppers can reserve up to five items per day and within one hour, they will receive an email or text confirming their items are on hold. The merchandise will be held in their selected store until close of business the next day. "It's been very well-received," said Tom Sands, executive vice president of Gap North America. He noted that Gap has found that shoppers who go into the store to pick up the reserved item also buy other products.

The "reserve-in store" option is part of Gap's strategy to offer customers access to shopping wherever and however they want it. Gap's online shoppers can also determine whether a product is in stock at a particular local store by checking online. And the retail chain is using its stores as mini-distribution hubs, shipping products from its stores to shoppers' homes.

Gap said its "reserve in store" option will not be available on Thanksgiving or the day after so that sales associates can focus on serving customers on one of the busiest days of the year. However, it will resume the service on Nov. 30 for Banana Republic and Dec. 2 for the Gap brand.

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