Carrier Serial Number Decoder: How to Read Any Carrier Unit's Age
By Andrew Norman, EPA 608 Certified HVAC Technician · Updated May 2026
Carrier is one of the most widely installed HVAC brands in North America. Carrier's serial number format has changed several times over the decades, and knowing which format your unit uses is essential for decoding the manufacture date.
Quick decode:
Use our Carrier serial number decoder tool — paste the serial number and get the manufacture date immediately.
Carrier Serial Number Formats by Era
Current Format (2004–Present) — Week + Year
Format: WWYYXXXXXXX
Example: 2506A12345 = Week 25, Year 2006 = June 2006
First 2 digits = week (01–52), next 2 = last 2 digits of year
1980s–2003 Format — Letter Year Code
The year is encoded in a letter prefix. Letters repeat on a 26-year cycle:
| Letter | Year | Letter | Year |
|---|---|---|---|
| A | 1973 / 1999 | N | 1986 / 2012 |
| B | 1974 / 2000 | P | 1987 / 2013 |
| C | 1975 / 2001 | R | 1988 / 2014 |
| D | 1976 / 2002 | S | 1989 / 2015 |
| E | 1977 / 2003 | T | 1990 / 2016 |
| F | 1978 / 2004 | U | 1991 / 2017 |
| G | 1979 / 2005 | V | 1992 / 2018 |
| H | 1980 / 2006 | W | 1993 / 2019 |
| J | 1981 / 2007 | X | 1994 / 2020 |
| K | 1982 / 2008 | Y | 1995 / 2021 |
| L | 1983 / 2009 | Z | 1996 / 2022 |
| M | 1984 / 2010 |
Carrier Brands: Bryant, Payne
Bryant and Payne are Carrier sister brands and use the same week-year serial number format in virtually all cases. Our decoder handles all three brands automatically.
Decoding Examples
Serial: 3710E56789
Week 37, year 2010 → September 2010
Serial: 0123G98765
Week 01, year 2023 → January 2023
What to Do With the Date
- Repair vs. replace: Carrier AC over 15 years or furnace over 20 years is approaching end of life.
- Refrigerant type: Units before 2010 almost certainly use R-22, which is very expensive to recharge.
- Real estate disclosure: Documents the manufacture date for seller disclosures.
For the fastest answer, use our Carrier decoder — it handles all format variations automatically.