Apple 2018: New iPhone 9 or xi? Name, release date and everything else we know about the latest handset ahead of today's event

The new iPhone is on its way.

Apple is expected to reveal the new, 2018 model of its handset soon, completely overhauling its iPhone line.

Much remains mysterious – and what doesn't is a little confusing. Here's everything we know about what's coming up, which will be continually updated as the latest news arrives.

Perhaps the most complicated thing about this year's rumoured iPhone line-up is exactly what it is. Or, rather, what they are.

Apple is expected to launch three new phones this year, rather than just the one. And while it has done that before, the way they are organised is slightly more complicated.

Until last year, the company had for three years released two phones: the normal iPhone, and the bigger Plus-sized ones, which would take the same name. Then last year it did the same, but also added the X, a model that sat between the two other phones in terms of size but featured a whole range of different, new and futuristic features.

This time around, Apple is expected to release two of those futuristic, more premium phones. They will, in short, be an updated version of the X, featuring much the same design but with a whole host of even more new features – in traditional Apple terms, they will be an Xs and an Xs Plus, though it's incredibly unlikely they'll actually be called anything like that.

And then they will also be joined by another, cheaper model. That will sit in between the two other phones in terms of size, but will be cheaper than both of them – while it will have much the same design, it will miss out on key features like the OLED screen.

Apple's now into a fairly predictable schedule with new iPhones. While it might break with that tradition, it would be a very unlikely and notable event.

So we can fully expect that Apple will follow that pattern and reveal the new iPhone at the beginning of September. The actual release will be a couple of weeks later, sometime around the 20th.

There have been rumours that Apple will delay the release of the cheaper phone for a couple more weeks, potentially pushing the full launch date into October or even November. It did that with the iPhone X, and so it wouldn't be all that strange to do the same this time around.

Usually, working out what the next iPhone will be called is simple enough: if it doesn't have an "s" after its number, you add one, and if it does already then you just increase the number by one. On and on it went, 5 become 5s, which became 6, which then gave way to the 6s, and then the 7 arrived.

Now, though, all of that is a lot more complicated. Last time around, Apple skipped straight from 7 to 8. And it also introduced the X, which threw the naming scheme entirely off, especially given the company insists that's pronounced "ten".

So it's not clear what Apple will do this time around. You might expect that the follow-up to the 8 would be called the 9, or the 8s, but then it will sound older than the X. And what will the follow up to the X be called – XI?

Probably not. It's entirely likely that Apple will either throw off the naming scheme entirely – like it has done with its iPads, which are just called iPad or iPad Pro – or introduce some new kind of naming scheme.

And we're not likely to find out before the actual release of the phone. Naming and other marketing decisions are much easier to keep secret than the phones themselves, so excepting any major leak then it might not be until Apple takes the stage that we finally learn the new iPhones names, if indeed they have one.

The new phones are to look largely like the iPhone X, though there might be small changes. Apple could further slim down the bezel, for instance.

That has been suggested by the leaked dummy models of the phone. While those might not be real, it's likely that any major design changes would have been leaked by now, so the phones could look something like those images even if they are not genuine.

But chief among the changes could be a major change by Apple to introduce colours back into its iPhone line. Apart from one-off red models, the boldest the company has got in recent years has been different hues of gold – but reports suggest that the new phones could come in a variety of colours, including blue and orange.

Little has been leaked about what exactly the new iPhone will do. While much has been rumoured about its look and what it will actually be, we don't know much about what's inside.

But with the phone being released in an "s" year, and so representing a tuning-up rather than an overhaul, it's likely the features will in fact be limited. The most notable will probably be the usual improvements rather than innovations, such as faster processor chips and improved camera guts.

There have been a host of other small rumours, including suggestions that Apple will make space for two SIM cards inside the phone, allowing users to have it on two numbers or two networks. There will undoubtedly be a range of those small upgrades, which commonly arrive with the "s" year.