Carrier Serial Number Lookup: Find Your Unit's Age

Type the 10-character serial number from the data plate to get the build year, fiscal week and an age range, with the rule shown below.

Last updated: 9 November 2026

How this is calculated

The two Carrier manuals we use describe a 10-character serial: four digits, one letter, five digits. The first two digits are a fiscal week, the next two are the year, and the letter is the manufacturing site.

1. Characters 1-2 are the week, 01 to 53. It is a Carrier fiscal week, so we never convert it to a calendar month. A week of 00 or 54 and over is an error.
2. Characters 3-4 are the year. 80 to 99 mean 1980 to 1999. 00 up to the as-of year's last two digits mean 2000 onward. Any other value, such as 50, or a year after the as-of date, shows Can't date this reliably. We do not date codes before 1980.
3. Character 5 is the site: A is Indianapolis, E is Collierville and G is Texas (ETP), as the manuals list them. Any other letter is shown as a site code that is not listed in the manuals we have.
4. Only the year is known to us, so the age is a range: the low figure counts whole years from 31 December of the build year, the high figure from 1 January. Neither goes below 0.

Worked example: 4808G12345 is fiscal week 48, year 2008, site G (Texas, ETP). On 9 November 2026 the age range is 17 to 18 years.

Limit. Both source manuals cover rooftop and outdoor equipment. Furnaces and air handlers with the same 10-character shape are assumed to decode the same way, which we have not confirmed. We do not decode Bryant, Payne or other brands that share a parent company.

Where the figures come from

1. Carrier 48TC*D08 manual, Appendix I, Carrier, as hosted on manualsdir.com. The serial layout.
2. Carrier R-22 application and service manual, Carrier, as hosted on manualslib.com. The same layout and the site letters.

We are independent of Carrier. To check coverage or warranty status, use Carrier's own warranty lookup on its website; this page only reads the date from the serial.

Where to find the serial number

The serial number is on the unit's data plate, usually a metal or foil label on the cabinet. The guide to finding the serial number on an AC, furnace or heat pump explains where to look. Copy all ten characters.

Age and expected life

To see how an age compares with typical lifespans, use the remaining life calculator, or read the guides on furnaces and air conditioners and heat pumps.