An overwhelming number of iPhone customers are choosing to buy the cheapest storage options possible, and they're quickly finding that 16GB simply isn't enough room.

A new survey carried out by camera app IceCream shows for the first time some concrete evidence about the iPhone's storage problem. The app asked UK mobile carrier Telefonica/O2 about iPhone storage space in the UK. What they found was pretty shocking: 91% of iPhones in the UK have 16GB or less of storage.

The data suggest that Apple's storage pricing strategy — it charges customers a lot more if they want the biggest, most functional level of storage — has yet to persuade customers to get out of their low-storage ghetto. With the iPhone 6, for instance, you can buy models with 16GB, 64GB, or 128GB of storage. The 16GB level will be mostly useless on an iPhone 6, so you're incentivized to pay extra for 64GB or 128GB.

So it's surprising that Brits are making do with the most minimal amount of capacity. The survey covers a mix of phones from the iPhone 5S, and 5C, through to the iPhone 6. The earlier phones had smaller storage capacity. But Apple has continued to update the iOS 8 operating system that runs on them, and that thing requires a huge amount of space all on its own. (Apple also seems to think 8GB of data just isn't enough anymore. The company hasn't introduced an iPhone offering 8GB since the iPhone 5C in 2013.)

16GB might sound like a lot of storage space, but it gets filled up quickly. The survey showed that 8% of iPhone users run out of storage every single day. And 22% of survey respondents said they run out of space at least once a month.

You might think that a move towards cloud storage and online backups means that we don't really need iPhone storage anymore. But there is a ton of software on your phone — apps, music and photos — and the phone needs storage to process it locally on your device.

The IceCream survey also found that 41% of people have over 500 photos on their phone. On average, a photo taken on an iPhone is going to be around 2MB in size. Having 500 of them on your phone can use up a gigabyte of storage space. And Apple's new method of storing photos means it's far more difficult to actually clear out your photos, meaning people are often stuck with more images clogging up their device than they realise.

But it's not just photos that are taking up room on iPhones. Even Apple's own software updates are causing a problem. The recent iOS 8 update to Apple's mobile software required a giant 4.6GB of free space on your phone in order to install. Most people don't have that much free space, so they were stuck using an outdated version of the operating system until they could connect to a computer.

Another issue for people using iPhones with small amounts of storage is the increasing size of apps. As screens have gotten bigger, and Apple has introduced support for new generations of processing chips, apps have increased in size also. A 2012 survey found that iPhone apps increased in size by 16% in just a matter of months.