The Hashtag on Mac Swaps Places With the Pound Sign

You press Shift and 3 expecting a hash, and get a pound sign instead. It is one of the most searched Mac questions in the UK, and the reason it keeps coming back is that the hashtag on Mac does not live on a fixed key at all. It moves depending on which keyboard layout your Mac is set to, and the pound sign moves with it, in the opposite direction.

That is why every answer you find contradicts the last one. Someone on a US layout tells you Shift+3. Someone on a British layout tells you Option+3. Both are right about their own machine and both are useless about yours.

Where the hashtag on Mac actually sits

On Apple's British layout, # is Option+3. Option is the key labelled alt on most UK MacBooks, sitting between Control and Command. Shift+3 on that same layout gives you the pound sign.

On Apple's US layout, those two swap over. Shift+3 gives you the hash, and Option+3 gives you the pound sign.

So the same two keystrokes produce the same two symbols on either layout, just crossed over. Wikipedia's summary of the British layout puts it plainly: the hash is assigned to Option+3, rather than a dedicated key.

That crossover is the whole problem. If you bought a Mac in the US and brought it to the UK, or restored one from a backup made on a differently configured machine, you can end up with the physical keys printed one way and the software mapped the other. Nothing is broken. The two symbols have simply changed places.

Why the advice online keeps contradicting itself

I went through the first page of UK results for both symbols, and the contradiction is sitting in Google's own top ten.

Search for the pound sign on a Mac and xe.com, published April 2025, tells you to press Option+3, and says that shortcut works seamlessly on both UK and US Mac keyboard layouts. On a British layout, Option+3 is the hash. Follow that on a UK MacBook and you get # exactly where you wanted a pound sign.

Further down that same page, Macworld gives the correct British answer: Shift+3 for a pound sign. Two results, one page of UK search results, opposite instructions for the same keystroke, and nothing to tell a reader which one describes their own Mac.

The hash pages themselves are better. Both of the how-to results above the fold name the two layouts separately and get them right. What none of page one does is tell you how to work out which layout you are on, which is the only thing that makes either answer usable.

How to tell which layout your Mac is actually using

Do not go by the printing on the keys. That tells you what Apple sold you, not what macOS is currently doing with it. Turn on the Keyboard Viewer and look instead.

Open the Apple menu, then System Settings, then Keyboard in the sidebar. Under Text Input, click Edit, and switch on Show Input menu in menu bar. A small flag or character appears in the menu bar. Click it and choose Show Keyboard Viewer.

Now hold Option. The on-screen keyboard redraws to show what every key produces with Option held down, so you can watch the hash appear on the 3 key, or fail to. Apple's own guide says to press one or more modifier keys (such as Option and Shift) to reveal the extra characters.

This takes about fifteen seconds and it ends the guessing permanently. Hold Shift instead and you will see where your layout puts the pound sign. It is the step worth doing before you try any keystroke anyone recommends, mine included.

When Option+3 does nothing at all

There is a second failure that no keystroke will fix. The top organic result in the UK for this question is not a how-to at all. It is a 2021 thread on Apple's own discussion forums from someone whose Alt+3 simply did not work, after they had tried what the forums told them.

The cause was not the keystroke, it was the input source. macOS can have several keyboard layouts installed at once and switch between them quietly, so your Mac can be physically British and logically something else entirely. The reply that solved it told them to open their input sources and make sure only one entry was listed, and that the entry was named British. You can read the original thread on Apple's forums.

So if nothing you press produces a hash, go to System Settings, Keyboard, Text Input, click Edit and look at the list. If there is more than one input source there, macOS is offering you a switch you may well be hitting by accident. Control-Space cycles between them, and that sits uncomfortably close to some very heavily used shortcuts.

Remove the layouts you do not want, or keep them and learn to glance at the menu bar before blaming the hardware. If one particular app has stopped accepting keystrokes altogether, that is a different problem, and force quitting it is the fix rather than anything to do with layouts.

Some British keyboards really do have a hash key

If you have used a British keyboard with # printed on a key of its own, you were not imagining it. The standard British PC layout carries an extra key beside Enter holding # and the tilde, a key Apple's own British layout does not have at all.

macOS ships an input source called British - PC to match those keyboards, and it is one of the layouts your Mac can end up set to. That is a third reason the advice conflicts: some UK users genuinely do have a dedicated hash key, so their instructions are no help to anyone typing on an Apple keyboard.

If you are using a third-party British PC keyboard plugged into a Mac, British - PC is probably the layout you want, and the hash will then be where the keycap says it is.

Four more routes when you just need one hash

By my count, the whole of page one offers three distinct ways to produce a hash between all of it: Option+3, Shift+3 on a US layout, and the Character Viewer. There are more than three, and some are better when the problem is occasional rather than constant.

• Character Viewer. Press Control-Command-Space, search for hash or number sign, and double-click it. It is the right answer on an unfamiliar machine where you do not want to change any settings.
• Keyboard Viewer. With it open you can click the key on screen instead of pressing anything, which also covers you if the physical key has failed.
• Text Replacement. In System Settings, Keyboard, Text Replacements, add a short trigger that expands to #. It then syncs to your iPhone and iPad over iCloud, which is the part most people miss.
• Dictation. Say the word hashtag and macOS types the symbol for you.

The Character Viewer and Keyboard Viewer both belong to a set of small built-in tools most people never open. Mac keyboard conventions catch people out in more than one place too, and moving files without a cut command is the other one I get asked about most.

None of these four fix the underlying layout confusion. They get you through the sentence you are trying to write, which some days is all you need.

Frequently asked questions

Why does Shift+3 give me a pound sign instead of # on my Mac?

Because your Mac is set to Apple's British layout, where Shift+3 is the pound sign and the hash sits on Option+3. On the US layout the two are reversed. Neither is a fault, and neither is worth changing unless you type one symbol far more than the other.

Where is the Option key on a UK MacBook?

It is the key labelled alt, between Control and Command, and there is one on each side of the space bar. Either works. Older UK keyboards sometimes print both alt and the Option symbol on the same key.

How do I type a hash without changing my keyboard layout?

Press Control-Command-Space to open the Character Viewer, search for hash, and double-click the symbol. For anything more than a one-off, set up a Text Replacement instead so a two-letter trigger expands to # everywhere, including on your iPhone.

My take

The hashtag on Mac is not a shortcut to memorise, it is a layout to identify. Spend fifteen seconds in the Keyboard Viewer, hold Option, and you need never search this again on any Mac, in any country, whatever is printed on the keys. Everything else here is a workaround for not having done that.

And if you are the person who keeps getting a pound sign where you wanted a hash, you are not clumsy and your keyboard is fine. You are simply on the layout the internet was not writing for.

Source: Use the Keyboard Viewer on Mac, Apple Support