Businesses regularly rely on online forms for collecting payments, conducting surveys, registering new customers and gathering leads, but a vast majority of consumers abandon these questionnaires and never return to complete them, according to a recent survey by business news site The Manifest.

The Manifest survey revealed that 81 percent of respondents admitted to clicking away from an online form recently and never returning to complete it.

The main reasons for doing so: form length and concerns surrounding online security. The survey found that more than a quarter of respondents — 27 percent — said they ditched an online form because it was too long, and slightly more — 29 percent — cited security worries. 11 percent said advertisements or upselling compelled them to leave, and 10 percent said they’d been provoked to abandon the process because of unnecessary questions.

The Manifest - What People Do After Abandoing an Online Form

The survey also suggested that once someone leaves a form, they’re not likely to return to it. 67 percent said they abandon the process entirely after quitting the form, compared to only 20 percent who admitted following up with the company later. And when people do return to a previously abandoned online form, the highest percentage — 30 percent — said it’s because they needed to access a resource they can’t otherwise obtain. An additional 20 percent admitted they’re willing to return if there’s an incentive, such as a contest, and nearly the same number — 19 percent — said they’ll go back and complete an online form if a company contacts them via or phone.

Consumers especially seem to dislike forms that aren’t mobile-friendly. Only three percent of respondents said they’d prefer to fill out a form on a mobile device, compared to 84 percent, who said they prefer a laptop or desktop computer. 13 percent still prefer a physical copy.

A majority of those polled — 67 percent — said they’d filled out at least one online form within the past week.

The Manifest survey polled more than 500 U.S. adults who said they’d filled out an online form within the past month.