On Memorizing Area Codes

July 5, 2026

TL;DR: Memorizing area codes sounds miserable, but it’s actually easy with the Dominic System: map every number from 00-99 to a person performing an action (78 = Genghis Khan riding horses), then tie that image to the corresponding region (Genghis Khan herding Kobe beef like a cowboy). Quizzing is much more effective after this, and the mnemonics tend to stick after just one or two viewings of the area code.

Learning area codes seems like a daunting task. I know what it’s like, I have a terrible memory and used to think I’d never bother due to the (perceived) difficulty. However, with the right approach, learning area codes becomes trivially easy. With the method I’ll describe here, I was reliably able to recall Brazil and Japan’s 2-digit area codes with just an hour of study each, and North America’s 3-digit area codes with two weeks of not-very-focused study. So have some faith, because if I can’t remember what I ate two days ago, and I can do this, I bet you can too.

This guide will be split into three parts. First, I’ll explain the mnemonic system that makes this all possible. Second, I’ll walk you through applying the system to memorizing area codes, first for Japan, then for North America. Finally, I’ll share my personal set of mnemonics that should give you a reference point and hopefully speed up the tedious up-front work required for this mnemonic system.

Part I: The Dominic System

The technique we’ll use for this is called the Dominic System, created by World Memory Champion Dominic O’Brien. This technique’s setup is where the bulk of the effort is, but also the bulk of the payoff. Set this up once, and you can re-use it for any numbers you want to memorize. It’s designed for memorizing long sequences of numbers (say, if you wanted to memorize the digits of pi), but it’s also perfect for our purposes.

The Dominic System works by turning the problem of recalling numbers into the problem of recalling images (surprise: our brains are great at this). It does this by taking the numbers from 00-99 and associating a unique person performing a unique action with each one. To aid with recalling these images, the digits 0-9 map to specific letters: OABCDESGHN (S and N are used because they’re more common/easier to use than F and I, but you can use whatever letters make sense for you). The person chosen for each image shares initials with the chosen letters. For example, in my set of mnemonics, the number 31 (CA) corresponds to Captain America. The action chosen for each image should be a distinctive action for the person, so for 31, the full image I have is “Captain America throwing a shield”.

Setting this up for all 100 two-digit numbers is time-consuming, especially since you want to pick images that have strong associations for you specifically. However, it makes everything that follows much simpler. I highly recommend you take the time to do this yourself. This is the hardest step of the entire process, so stick with it. You will then need to memorize the mnemonic chosen for each number, but you can do this while practicing area codes, you don’t need to make it a separate step. One way to get extra “reps” in is to recall the image associated with every two-digit number you see. The current time is a great source of two-digit numbers, and so are (real-life) license plates.

And a tip: you do not need to force yourself to stick to the rule that the person needs to match their initials. Whatever is memorable is best (and it can be hard to even think of a person with some initials). For example, 50 for me is “Abraham Lincoln flipping a coin”, and the thought process is that the number 50 makes me think of situations that have 50-50 odds, and are thus a coin flip. Abraham Lincoln is on the penny, and so there’s my mnemonic. Similarly, 80 (HO) is “Santa Claus delivering presents” because Santa says “Ho Ho Ho”. Note that this is kind of a bad choice, since SC already corresponds to 63, which can lead to confusion while you’re memorizing your list of mnemonics. However, once your list becomes second nature to you, this stops being a problem.

Now, the way the Dominic System is intended to be used involves breaking down large numbers into a series of paired two-digit numbers. For example, if we wanted to memorize 31207831, we’d first split it into 31-20 78-31. We then take the person from the first half and the action from the second half of each pair. In my system, 20 is “Barack Obama giving himself a medal”, and 78 is “Genghis Khan riding horses”. So, 31-20 78-31 becomes “Captain America giving himself a medal, then Genghis Khan throws a shield”. This is much easier to remember than 31207831. Thankfully, our task will be even easier than this.

Part II: Application

Two-Digit Codes

Once you understand the Dominic System and have a set of mnemonics ready to go, I recommend trying it out with Japan’s area codes. This is a good place to start thanks to Japan’s area codes being (roughly) organized from north to south, with a bit of chaotic shuffling along the way.

To use the Dominic System here, don’t worry about the paired two-digit technique. Japan’s area codes are only two digits long (if you ignore the leading 0, which you should), so the mnemonics you chose in Part I are enough on their own.

Japan only has 59 area codes, so what I recommend is to go to this quiz, enable “Force Correct Click” and “Recycle Missed Answers”, and run through the whole thing until you get every code correct on the first try. For each code, think carefully about the corresponding image and how it corresponds to that area. Once you’ve got a solid handle on these, turn off “Borders” and “Shading” to practice these the way you would in a real game, without seeing the area code boundaries.

For example, the area code 078 (which I’ll treat as 78) is the area code for the region around Kobe. My task is now to associate “Genghis Khan riding horses” with the Kobe area. You can use anything you know about the area to drive the association. The name of a major city, the shape of the region, anything you make up, whatever it is, as long as you find a memorable connection, you’re doing it right. In my case, I know that Kobe is famous for its beef, so I imagine Genghis Khan on his horse herding cows like a cowboy. Thanks to this, whenever I see the number 78, I think of Genghis Khan, and this image helps me zoom in on and click Kobe every time.

For a less straightforward example, 019 corresponds to Iwate prefecture, and to “Anchorman doing a news report” in my mnemonic list. For this, I imagine Ron Burgundy (the anchorman in the movie Anchorman) showing up, not finding anything newsworthy, and saying “I wait” as he waits for something interesting to happen. “I wait” is similar enough to Iwate (not how you pronounce that) that the memory sticks. One last example: 045 is Yokohama and “Dr. Eggman flying in his egg-mobile”, and Yoko is similar to yolk, which is in eggs.

As you can see, the connections made can be super tenuous, and the beauty is that they’ll still work! If Japan comes easily, I recommend following it up with Brazil, which also has well-grouped two-digit area codes.

Three-Digit Codes

And now we arrive at three-digit codes. The approach here is similar, though now we make use of the pairing system described at the end of Part I. In order to convert a three-digit number into an image, duplicate the central digit, then proceed as usual. In this way, an area code like 319 becomes 31-19, or “Captain America doing a news report”, which he does in Cedar Rapids, Iowa, because Cedar is Captain America’s favorite tree (starts with the same letter). As always, the rules are flexible. 414 is “Diego Armando turning water into wine”, but 414 is DAD and Milwaukee, so I remember “Diego Armando turning water into milk”, since he loves coffee, milk goes well with coffee, Milwaukee can be shortened to Milkee, and 414 is DAD and this seems like a dad joke to make about Milwaukee. 314 is St. Louis, so I skip the mnemonics altogether for this one, since surely they needed pi to architect the Gateway Arch in St. Louis.

Ideally, you could learn these in chunks by region to avoid being overwhelmed, but I found no pre-existing quiz for doing so on helloquiz. As such, the method I used is to do this quiz in anki mode, meaning that it schedules reviews for the cards you’ve seen on a timer based on how well you remembered them the last time they came up. This ensures that each day you open the quiz, it first shows you the area codes you’ve already seen before introducing additional ones. Do this enough times, and you’ll eventually have seen every card and reviewed the tough ones enough times to have them all memorized. As always, I recommend having the “Force Correct Click” button on when learning these.

If you’ve already memorized Japan and Brazil, you should find doing this a breeze, even with the lack of ordering that the US area codes have.

Part III: My Mnemonics

As a way to give y’all a base to get started with, here’s my list of mnemonics. You can edit your own list here. Make sure you don’t just blindly reuse my list as-is. Replace entries you don’t understand with entries of your own if you want them to be effective. I would love to share a list with only references everyone would get, but as I mentioned earlier, compiling this list is difficult and takes a long time. I spent a bit over a week putting this together, and still feel some of these were quite forced, but now it’s ingrained and works well, so I can’t complain.