What Does ASAP Mean? As Soon As Possible, Its Military Roots and Better Ways to Ask

ASAP might be the most used abbreviation in office life. It turns up in emails, chats, text messages and sticky notes on desks. It's also one of the most misunderstood, because 'as soon as possible' means different things to the person asking and the person reading. Here's what it means, where it came from, how to say it and what I'd write instead when timing matters.

ASAP: the short definition

Merriam-Webster lists ASAP as an abbreviation for as soon as possible. Cambridge gives the same meaning, with the example 'Could you let me know asap if this is something you would consider?' Dictionary.com treats it as an adverb too, meaning without delay, and says the word form was first recorded in 1990 to 1995.

You'll see it in capitals, ASAP, in lower case, asap, and occasionally with full stops, A.S.A.P. Dictionary.com lists all three. They all mean the same thing.

Saying ASAP out loud

There are two accepted ways. Merriam-Webster gives both pronunciations: letter by letter, 'ay-ess-ay-pee', and as a word, 'ay-sap'. Wiktionary records the same pair in British and American English.

Neither is wrong. In my experience, 'ay-ess-ay-pee' sounds slightly more formal and 'ay-sap' more casual. Pick the one people around you use.

From the military to the inbox

ASAP is older than email. Wiktionary traces it to the 1950s and says its first known use is in a book by Captain Annis G Thompson, who was involved in the Korean War, called The Greatest Airlift, published in 1954. It notes the original meaning in the military was 'as soon as militarily possible'.

That origin explains the tone. ASAP was built for chains of command, where an order means drop what you're doing. When it moved into offices, it kept some of that weight, which is why it can feel like pressure even when it's meant as a polite nudge.

Why ASAP causes trouble at work

The problem is that 'possible' is doing a lot of work. To the sender, ASAP might mean within the hour. To the reader with a full diary, it might mean by Friday. Neither person is being unreasonable, but the deadline only exists in one head.

• It hides the real deadline. If you need something by 3pm, ASAP doesn't say so.
• It stacks up. When everything is ASAP, nothing stands out as urgent.
• It can sound sharp. In capitals at the end of a short email, ASAP can read as impatient.
• It doesn't explain why. People prioritise better when they know what's riding on it.

What to write instead of ASAP

Instead of	Try	Why it works
Send it ASAP	Could you send it by 3pm today?	A clear deadline
Need this ASAP	I need this before the client call at 2	The reason sets the priority
Reply ASAP	Could you reply by end of day?	Gives a realistic window
ASAP please!	Whenever you can this week, ideally Wednesday	Friendly with a target

If end of day is the target, it helps to know how people read it. My guide to EOD covers that one, and my guide on how to write a professional email has more on getting requests answered without sounding pushy.

ASAP in texts and personal messages

With friends, ASAP is usually lighter. 'Call me asap' can mean 'I've got news'. 'Need pizza asap' is a joke about hunger. These are made-up examples, but they show how the stakes drop outside work. Still, if a friend or family member sends 'call me ASAP' out of the blue, it's worth ringing quickly in case something's wrong.

ASAP in sentences: getting the grammar right

ASAP works like an adverb, so it sits where 'soon' or 'quickly' would. 'Please reply ASAP' and 'I'll call you asap' both read naturally. You'll also hear 'at your earliest convenience', which is the formal, softer cousin often used in letters, and 'as soon as you can', which sounds friendlier than the abbreviation.

One common slip is 'as ASAP as possible', which repeats itself. Another is adding 'ASAP' to a request that has no deadline at all, which trains people to ignore it. And if you're writing to someone whose first language isn't English, spell it out. Abbreviations are easy to misread, and 'as soon as possible' is clearer for everyone.

It also helps to pair ASAP with a reason when you do use it. 'ASAP please, the printer needs it by noon' tells the reader what's at stake, and people are far more likely to move things around when they can see why.

Another time-related abbreviation, with a very different second meaning, is explained in the ATM meaning page.

Words that mean the same as ASAP

Wiktionary lists 'stat' as a synonym, the word you'll hear in hospital dramas, and gives 'at leisure' as the opposite. Other languages have their own versions. Wiktionary notes the Dutch abbreviation z.s.m. and the Japanese 'naruhaya', a clipped form of 'as early as possible'. Wiktionary also lists ASAP itself as used in Polish, Finnish and Estonian.

If you want to say now rather than as soon as possible, see the guide to RN in texts.

My rule for ASAP with clients

I don't send it to clients. If something's urgent, I say when I need it and why, in one line. It's kinder, it gets faster answers, and it saves the real 'drop everything' moments for when they matter. And if a client sends ASAP to you, reply with a time: 'I'll have it with you by 4pm.' That turns a vague demand into a promise you can keep. For other workplace shorthand, FYI is the one that means no action needed at all.

Frequently asked questions

What does ASAP stand for?

As soon as possible. Dictionary.com also defines it as without delay, promptly.

How do you pronounce ASAP?

Either letter by letter, 'ay-ess-ay-pee', or as one word, 'ay-sap'. Merriam-Webster lists both.

Where did ASAP come from?

Wiktionary traces it to the 1950s military, originally meaning 'as soon as militarily possible'.

Is ASAP rude in an email?

It can sound impatient, especially in capitals. A specific deadline usually lands better.

What's a synonym for ASAP?

Wiktionary lists 'stat'. The opposite is 'at leisure'.

Is asap in lowercase OK?

Yes. Dictionary.com lists ASAP, asap and A.S.A.P. with the same meaning.