Trane date code: year and fiscal week in the serial
Last updated: 2026-10-28
Trane's 2026 Product Handbook says its serial numbers identify “the year and fiscal week of product manufacture.” In current 10-digit serials, digits 1–2 are the year and digits 3–4 the fiscal week. Older 9-digit serials use one character for the year, then two digits for the week. Trane's 9-digit example is M124X04CF.
The 10-digit serial
Trane ten-digit serial
Digit
What it means, as Trane describes it
1st
Second-to-last digit of the year; a blank space when it is 0
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Where Trane's table overlaps or is unclear
2004 is in both formats. Trane gives nine-digit serials for “1980 thru 2004” and ten-digit serials for “2004 to present”.
For 2002 to 2009 the year code is one digit, or “9 or 09” for 2009. The ten-digit table says the first digit is a blank space when it would be 0. The handbook does not show how a blank first digit looks on a label.
Trane calls the week a fiscal week. The handbook does not give Trane's fiscal calendar.
Trane also says accessories may have only three digits for the date code. Coils with a three-digit date code are an exception to the nine-digit format.