Information gathered from the web: Serial numbers on Yamaha guitars repeat every ten years due to the way they are formed. The first letter indicates the last digit of the year of production.

(Their numbering system began with “H” for 1.) The second letter indicates the month. The first two numbers indicate the day of the month. The last three numbers represent order of production on the day the guitar was made. Example: hm02316 = the 316th unit made on June 2 of 1961, 1971, 1981, 1991, or 2001. First Letter Years H 1961, 1971, 1981, 1991, 2001 I 1962, 1972, 1982, 1992, 2002 J 1963, 1973, 1983, 1993, 2003 K 1964, 1974, 1984, 1994, 2004 L 1965, 1975, 1985, 1995, 2005 M 1966, 1976, 1986, 1996, 2006 N 1967, 1977, 1987, 1997, 2007 O 1968, 1978, 1988, 1998 P 1969, 1979, 1989, 1999 Q 1960, 1970, 1980, 1990, 2000 Second Letter Month H January I February J March K April L May M June N July O August P September X October Y November Z December A lot of people have written in to say, “Hey! My Yamaha serial number looks nothing like this!” To you folks, we offer the following: Several other serial number configurations used by Yamaha over the years.

If you still can’t figure it out, please see Yamaha contact info at the bottom of this page. Alternate serial number configurations for Yamaha Classical and Acoustic Guitars Custom Shop, Made in Japan, 1966-1985: 001-1042 in sequence Custom Shop, Made in Japan, 1986-1990: Letter-####, like so: J7012. The letter at the beginning represents the month, so J would be March (see chart above). The number following the letter is the year, in this case 7 for 1987.

The last three numbers indicate unit number. 012=12th unit. Custom Shop, Made in Japan, 1991-1996: Letter-letter-###-letter, like so: HP213J. Using the charts, we see that H=1991 and P=September.

The serial number is essential in determining whether a car is a genuine ESP optioned vehicle. Despite certain parts being rare, most features of the XD ESP.

213=unit number; and that last letter is an internal code. Custom Shop, Made in Japan, 1997-2003: Letter-letter-###, like so: NK333. Using the chart, N=1997 and K=April. The three numbers are again, unit number. Unit number 333 in this case.

Custom Shop, Made in Japan, 2004-: Letter-letter-letter-###-letter, like so: QLY111C. Q=0 and L=5, so 2005. 111 is the unit number; and the final letter is an internal code.

Yamaha Music Craft, Made in Japan, 1997-1999: Letter-letter-###-letter, like so: ON521J. (That first letter is an “oh” not a zero.) The first letter is the year; O=1998. The second letter is the month; N=July. The three numbers are the unit number; this started over each month at 500, so unit number 21. The final letter is an internal code.

Yamaha Music Craft, Made in Japan, 1999: Letter-letter-###, like so: PM222. The first letter is the year; P=1999. Second letter is the month; M=June. The last three numbers are the unit number.

During 1999, they starting the count each month at 200 rather than 500. (See previous entry for Yamaha Music Craft for more on the numbering.) Yamaha Music Craft, Made in Japan, 2001-: Letter-letter-letter-###-letter, like so: QIL123A.

The first two letters are the year; Q=0 and I=2, so 2002. The third letter is the month; L=May. The three numbers are the unit number; 123. The final letter is an internal code. Tenryu/Wada Factory, Made in Japan, 1946-1968: #####.

Just five digit numbers in sequence. No year of manufacture can be determined. Tenryu/Wada Factory, Made in Japan, 1969-1984: ######. Six numbers, like so: 710502. The first two numbers are the year. In this case 1971.

The second two numbers are the month; here, May. The final two numbers are the unit number. Tenryu/Wada Factory, Made in Japan, 1985-1986: ######. Six numbers like so: 860021. The first two numbers are the year; 1986. The last four numbers are the unit number; 21. Kaohsiung Factory, Made in Taiwan, 1971-2001: ########.

Eight numbers, like so: 10918111. The first number is the year; 1971. The second and third numbers are the month; 09=September. The fourth and fifth numbers are the day; 18th.

The final three numbers are the unit number; 111. Kaohsiung Factory, Made in Taiwan, 2001-: Letter-letter-letter-######. Three letters, six numbers, like so: QIM183112. The first two letters are the year; Q=0 and I=2, so 2002. The third letter is the month. Krichalki pro zdorovij obraz zhizni prikoljnie. The first two numbers are the day; 18th. The final four numbers are the unit number; 3112.