Apple Pay is coming up short for many people who attempt to use the mobile payment service at the register.

A survey from research firm Phoenix Marketing International found that 68 percent of respondents who have used Apple Pay had encountered an issue when making an in-store purchase.

The leading compliant made by nearly half of respondents was that retailers’ sales terminals took too long to record a transaction. Other problems: employees who didn’t know how to process sales with the mobile wallet (42 percent); errors in how the sale posted (36 percent), like a transaction appearing twice; and out of service Apple Pay terminals (27 percent). Almost half of the Apple Pay users surveyed (47 percent) found that the particular store they visited didn’t accept Apple Pay although the retailer was supposed to support the service.

Apple Pay launched in October and is accepted at 700,000 locations and supported by 2,500 banks in the U.S., CEO Tim Cook said at an event earlier this month. Retailers that accept Apple Pay include Macy’s, Subway, Nike, Whole Foods and McDonald’s. Apple hasn’t shared details on when the service will be expanded internationally.

People appear eager to use Apple Pay, with 59 percent answering that they have asked store employees if the merchant accepts payments with the service. Using Apple Pay requires linking a credit or debit card to the service.

Ease of use compared to swiping a credit card (74 percent) and the hip factor associated with Apple Pay (59 percent) were the top factors for using the service. People were also interested in Apple Pay for the security features, with 58 percent saying it’s safer than swiping a credit card that stores sensitive information on a magnetic strip. Instead, Apple Pay transactions use tokenization to replace credit and debit card numbers with a special code that is exchanged between merchants and banks.

A majority of respondents used the mobile payment system in Apple stores (46 percent), followed by McDonald’s (36 percent) and Macy’s (30 percent). Apple Pay was also popular at Nike stores, Whole Foods, and Walgreens.

CurrentC, a competing mobile wallet being developed with backing from Walmart and CVS, may struggle to find users, judging by the survey. Unsurprisingly, 63 percent of iPhone users would prefer to only use Apple Pay and 27 percent would use or consider using both services. Among smartphone owners in general, 54 percent would prefer to exclusively use Apple Pay and 23 percent would use or consider using Apple Pay and CurrentC. Still, the survey noted that there’s room for both mobile payment systems in the market.

While non-iPhone users polled may be interested in using Apple’s mobile wallet, the service isn’t available on other mobile platforms.

The survey polled about 3,000 people, of which 302 have used Apple Pay to make a purchase.

Apple didn’t reply to a request for comment.