Apple Serial numbers are not some random number but actually contain useful information about your Mac.
Apple Mac Serial Number Format:
The serial number can be separated into two sections for older 11 character & new 12 character type serial number as shown in table below:
Old Serial Number Example:
Serial Number: CK05241AU9B
CK -> Ireland (Cork)
0 -> Year 2010
52 -> Week 52
41A -> Production Line – 316
U9B -> MacBook1,1
New Serial Number Example:
Serial Number: C02K34U9DKQ1
C02 -> China (Quanta Computer)
K -> Year 2013 (1st half)
3 -> Week 3
4U9 -> Production Line – 1233
DKQ1 -> MacBookPro10,1
Type (11 or 12) Character
There are generally two similar formats of serial encoding:
- Old 11 character format
- New 12 character format
Location (LL or LLL)
This value encodes the manufacturing location. It is often more descriptive than “Made in China”, since it also reveals the company and the city of manufacture.
For example, “F5K” means Flextronics, USA and “QT” means Quanta Computer, Taiwan.
One of the important locations for old-style serials (11 characters) is “RM”. It means that the model was refurbished. For new-style serials you have to call Apple support to know this.
The year of manufacture is also represented by an alphanumeric code.
The third or fourth character (Y) of the serial number represents the year the device was manufactured in, and for new-style serial, whether the device was manufactured in the first or second half of the year.
For refurbished models it is unknown whether it is replaced by the re-manufacturing year.
For old-style serials it is always a digit that encodes the last digit of the year. For example, 7 means 2007 and 1 means 2011. Only 0 to 9 digitis are used for year encoding. Old-style serials are out of use starting with 2013, so 3 means 2003 not 2013.
Week (W or WW)
Week encodes the actual manufacturing week of each model. This week has nothing in common with ISO 8601, and appears to be encoded literally as 7-day sequences starting from January, 1st.
Since each year has either 365 or 366 days, 53rd week is extremely rare, and you are lucky to have such a serial.
For old-style serials, the week is simply encoded in plain numeric digits with leading zeroes:
01 -> Week 1
53 -> Week 53
For new-style serials an alpha-numeric code is used. The encoded year (Y) half also counts, and means that 26 weeks is added for the second half.
Production line (SSS)
Production line is believed to encode the manufacturing line or some identifier used by the assembly engineers. It is calculated as a sum of three alpha-numeric characters, which themselves represent a modified base34 code excluding O and I.
The actual formula is as follows:
(base34[S1] * 68) + (base34[S2] * 34) + base34[S3] = production line
SSS = 4U9
(4 * 68) + (28 * 34) + 9 = 1233
That allows to encode a total of 3400 production lines from 0 to 3399.
From the nature of the production line code there often exist multiple ways of encoding each value.
680 could be encoded as 0L0, 1J0, 2G0, 3E0, …, 920
2400 could be encoded as KYL, LWL, MUL, …, Z4L.
It was experimentally discovered that the first N encoded values are always valid, and starting with the first invalid value there will be no valid ones.
From this data it could be assumed that the encoding type is incremented for each model produced from the same line.
So 0L0 and KYL are the first copies produced, and 920 with Z4L are the last copies.
Platform model (PPP or PPPP)
Last 3 characters (for legacy serials) or last 4 characters (for new serials), encode the actual platform/model of this exact piece of the hardware.
This is probably the most useful part of the serial, since it allows you to get the detailed description of your hardware directly from the dedicated Apple Specs portal.
To do so you need to modify the following URL to contain your real platform model value instead of PPP or PPPP and follow it in your browser:
Legacy Model: http://support-sp.apple.com/sp/index?page=cpuspec&cc=PPP
New Model: http://support-sp.apple.com/sp/index?page=cpuspec&cc=PPPP
U9B -> MacBook1,1
DKQ1 -> MacBookPro10,1