# Apple's Sales Have Grown So Much That It's Running Out of 10-Digit Invoice Numbers

#### MacRumors

##### macrumors bot
Original poster

Currently, when Apple sends an invoice to its customers and business partners, the recipient gets an invoice number that is entirely numeric and spans 10 digits.

According to a post on Reddit citing a letter from Apple called "Change in Invoice number format," the company has drafted so many invoices that it's close to going through all possible permutations for these 10-digit numeric codes, necessitating a switch to an alphanumeric system.

This means that instead of a basic 10-digit number, Apple's system will now include two alphabet characters followed by eight numbers, for example: "AB12345678." These changes will begin applying to all invoices issued "approximately after the third week of February 2019."

As explained in the Reddit thread on the topic, there are a total of 10 billion possible invoice numbers available to Apple through its current 10-digit all-numeric system, suggesting Apple is nearing 10 billion invoices sent worldwide for as long as it's used this system. Apple sends an invoice every time an order is made on the Apple Store app, website, or in-store, with each order receiving a unique invoice code.

When adding in two letters to the beginning, Apple's invoice code possibilities increase to around 67.6 billion. Redditor nalexander50 explained the math in greater detail:
Wow, that's a lot of orders! If I am remembering my college combinatorics course properly, a 10 digit numeric only code would cover 10 Billion orders. Each position in the number has 10 possible values (0-9) and there are 10 values total. Multiplying it out, 1010 = 10 Billion.

Changing the first two positions to letters vastly increases the possibilities. For the first two positions, there are 26 possible choices (a-z), and the remaining 8 positions have the same 10 (0-9) choices. Multiplying it out, 262 * 108 = 67.6 Billion invoices. Since it has taken this long to creep up on 10 Billion, I figure that an additional 67 Billion will last a while.
With yesterday's update to the Apple Store iOS app, the company also made it possible to get to your order invoices from within the app. To do so follow these instructions: open the app, tap the circular profile symbol at the top right of the Discover tab, scroll down to My Orders, tap on one, tap Print Invoice, then sign in to your Apple ID. On the invoice, the invoice number is located in the Additional Information section at the very bottom of the page.

Article Link: Apple's Sales Have Grown So Much That It's Running Out of 10-Digit Invoice Numbers

#### jsmith189

##### macrumors 68000
Y2K APPLE'S OVER.

#### markfc

##### macrumors 6502a
Hang on, if they send an invoice with every App Store purchase, how have they not hit this sooner?

Mathematically it doesn’t make sense?

JeffyTheQuik

#### iPhysicist

##### macrumors 65816
Just make it Hex. Problem solved for a long time. Maybe even think of adding a digit - insane thought I know.

#### duervo

##### macrumors 68020
Hang on, if they send an invoice with every App Store purchase, how have they not hit this sooner?

Mathematically it doesn’t make sense?
Apple Store app, not App Store.

#### Secondempire

##### macrumors member
Hang on, if they send an invoice with every App Store purchase, how have they not hit this sooner?

Mathematically it doesn’t make sense?
This is about the Apple Store, not App Store. Apple Store is where they sell physical goods.

#### Rudy69

##### macrumors 6502a
Hang on, if they send an invoice with every App Store purchase, how have they not hit this sooner?

Mathematically it doesn’t make sense?
App Store orders are different and use a different system.

#### manu chao

##### macrumors 604
When adding in two letters to the beginning, Apple's invoice code possibilities increase to around 67.6 billion. Redditor nalexander50 explained the math in greater detail:
Changing the first two positions to letters vastly increases the possibilities. For the first two positions, there are 26 possible choices (a-z), and the remaining 8 positions have the same 10 (0-9) choices. Multiplying it out, 262 * 108 = 67.6 Billion invoices. Since it has taken this long to creep up on 10 Billion, I figure that an additional 67 Billion will last a while.
Not quite, its 26 * 26 * 10 billion = 6.76 trillion.

EDIT: I misread the original statement as 10 digits + two letters. In fact it says two letters + 8 digits.

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#### I7guy

##### macrumors Core
This is quite the first world problem to have.

#### Gyroworld

##### macrumors member
This is quite the first world problem to have.
It's actually just a math problem
[doublepost=1521815901][/doublepost]
Not quite, its 26 * 26 * 10 billion = 6.76 trillion.
That is incorrect.

It's 26^2 * 10^8 not 26^2 * 10^10.

67.6 billion is correct.

#### 4jasontv

##### macrumors 68040
This is quite the first world problem to have.
I don’t think this is the first problem the world has ever had. For one thing it’s not really a problem because they seem to have avoided any issues. Secondly, if it was an issue, most people would not have been involved. Third, disease and famine are problems that impact most of the world, and they seem to have existed prior to this.

/s

#### whooleytoo

##### macrumors 604
It's funny, I'd have thought just adding more numeric digits would be easier.

Add an extra digit or two, and partners might be ok without any change (worst case scenarios is they might have to increase the size/length of their numeric fields in code and the UI), but changing to alphanumeric means the order number needs to be handled as a string, which requires the storage and any queries to be changed.

Anyway, nice problem to have! I wonder if it's truly indicative of the number of orders, since I'd imagine few companies start with order '00000000001', most probably pad their starting order number.

#### manu chao

##### macrumors 604
It's actually just a math problem
[doublepost=1521815901][/doublepost]

That is incorrect.

It's 26^2 * 10^8 not 26^2 * 10^10.

67.6 billion is correct.
Ok, that was misreading the original statement as two letters + 10 digits.

SMH

#### npmacuser5

##### macrumors 65816
Wonder how they will manage? Just the opposite here, running out of check numbers!

Marekul

#### shareef777

##### Suspended
That begs the question of why not use alphanumeric for all 10 positions?

#### eagle33199

##### macrumors member
I don’t think this is the first problem the world has ever had. For one thing it’s not really a problem because they seem to have avoided any issues. Secondly, if it was an issue, most people would not have been involved. Third, disease and famine are problems that impact most of the world, and they seem to have existed prior to this.

/s
I don't think you understand what the phrase "first world problem" actually means...

12/31/1999!

coolfactor

#### coolfactor

##### macrumors 601
They'd probably skip a few letters, or would be wise to — I and O are two that can be mistaken for numbers.

#### Marekul

##### Suspended
It's funny, I'd have thought just adding more numeric digits would be easier.

Add an extra digit or two, and partners might be ok without any change (worst case scenarios is they might have to increase the size/length of their numeric fields in code and the UI), but changing to alphanumeric means the order number needs to be handled as a string, which requires the storage and any queries to be changed.

Anyway, nice problem to have! I wonder if it's truly indicative of the number of orders, since I'd imagine few companies start with order '00000000001', most probably pad their starting order number.
Longer invoice number messes up layouts in print and web, also probability of a wrong digit increases with number of digits. String vs internet representation doesn’t make a lot difference in backend maybe a Little refactoring here and there.... but you rarely do operations on invoice numbers...

#### Saipher

##### macrumors 6502
First world problems. Good for Apple though

#### duervo

##### macrumors 68020
They aren’t gonna “run out”. Unless they’re totally incompetent, there’s most likely a system already in place to switch over to a different one with alphanumeric characters in an invoice number.

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#### nvmls

##### macrumors 6502a
There's a dongle for that..

#### Apple blogger

##### macrumors 6502a
Why couldn’t they just add a “year” after the invoices and begin again each year.. for eg. 1234567890-2018 1234567890-2019

I think “we built it from the ground up” applied here too...

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