This weekend, I popped into the West 14th Street Apple Store to check out the new Apple Watch colors. But I ended up seeing something a lot more interesting: a mobile point of sale terminal.

Not the exact model, but you catch my drift.

Among the sleek, wooden tables and Jony Ive designed electronics, there was a hunk of black plastic floating between Apple employees. While it’s definitely in Apple’s ethos to make the payment process as easy as possible — and what’s easier than bringing the point of sale to the customer as opposed to marching them to a cash register?— the actual credit card reader stuck out like a sore thumb.

It doesn’t have to be like this. Inside of each iPhone 6 and 6s is an NFC chip that can not only send out the signal that enables Apple Pay, but can recieve a signal as well. That means, potentially, that the iPhone (or the iPad) could be a full-featured Apple Pay point of sale terminal.

Imagine all of those small business owners who already use Square readers to accept cards. Imagine making accepting Apple Pay as easy as opening up an app. No external hardware to deal with — just two phones.

Sure, you’d still need to have some other POS terminal around to read cards. But the goal here is to make using the card reader seem like a huge pain compared to Apple Pay. Tim Cook tried to make this argument when he introduced Apple Pay last September. He showed two videos of a shopping experience: one with a wallet and credit card and one with Apple Pay. “That’s it!” Cook shouted after the Apple Pay video finished, attempting to underline just how easy Apple Pay was compared to a card.

It’s a funny video, mostly because Apple really went out of their way to make wallets seem terrible (sometimes cards get a little stuck in them! and what if they ask to see your ID!?).

But imagine going to the Apple Store and buying an Apple Watch. Imagine how easy and sleek it would be to pay just by holding your phone up to an employee’s phone. Imagine how antiquated it would seem to pay with a card, and for the employee to pull out the hunk of black plastic that it requires.

There are a few companies trying to make point of sale terminals as sleek and sexy as an iPhone. The aforementioned Square got a shoutout on Apple’s stage (their NFC-enabled reader is coming soon), and Poynt got some major press last fall.

The biggest thing holding these companies back is that you have to buy external hardware. There are already millions of iPhones with NFC readers inside of them. All they need to do is flip a switch.