Grand Seiko Chronometer

We guarantee free repair and adjustment service against any defects on the watch body (movement and case) and metallic band, provided that the watch was used as described in the instruction manual. The period of a worldwide guarantee for Grand Seiko is two years from the date of purchase.

In order to apply for this service under the guarantee, you need to present the guarantee repair coupon enclosed in the worldwide guarantee for Grand Seiko to an authorized Grand Seiko dealer or any member of the Grand Seiko service network. The worldwide guarantee for Grand Seiko will be provided by an authorized Grand Seiko dealer at the time of purchase.

If you plan to purchase a Grand Seiko in Japan and take it out of Japan, make sure to receive a worldwide guarantee for Grand Seiko at the time of purchase.

Servicing of Grand Seiko watches will be performed only at the Service Centers listed in the Grand Seiko International Service Network which are marked with [S.R.], [S.A] or [S.A]*. If your area is not listed in the network, please contact the nearest Authorized Seiko Service Center.

* Repairs such as minor adjustment, strap replacement or battery change will be carried out at the nearest Authorized Seiko Service Center.

[S.R.] Service Reception
[S.A.] Service Available
[S.A.]* Service Available but models with specific characteristics are to be sent to Japan for repair

What is "Grand Seiko Standard"?

Grand Seiko Standard is a Seiko-exclusive accuracy standard for mechanical watches which has been established to ensure superior performance of Grand Seiko mechanical watches irrespective of the differences in environmental conditions in which a watch is used. "Grand Seiko Standard Inspection, " which measures gain / loss (daily rate) under various environments, is carried out at the manufacturing plant for 17 days in total, and only mechanical watches that satisfy the standard are given the title of "Grand Seiko."

The Grand Seiko Standard differs from the other recognised chronometer standards in two important respects. While most accuracy standard testing is done for five positions at two temperatures, the Grand Seiko Standard tests six positions at three temperatures. This is because the Grand Seiko Standard seeks to replicate real world conditions. The sixth position, namely the 12 o’clock upright position, is the way many people place their watch when not wearing it. In addition, the extra temperature rating is closer to body temperature. The idea is simple - to test the watch under conditions similar to actual use.

* Inspection of the movement for the Grand Seiko Standard Inspection Certificate is made prior to casing. Movement performance is carefully measured in the static position under scientifically controlled conditions.
* The accuracy of the watch may vary depending on the actual usage conditions and may differ from the certified accuracy.

What is "Grand Seiko Standard Inspection Certificate"?

The Grand Seiko Standard Inspection Certificate certifies that the measured values of a movement, which were measured in a scientifically controlled environment in the manufacturing plant, have passed the Grand Seiko Standard Inspection. The certificate is printed with the caliber number, movement serial number, and case serial number.

* Inspection of the movement for the Grand Seiko Standard Inspection Certificate is made prior to casing. Movement performance is carefully measured in the static position under scientifically controlled conditions.
* The accuracy of the watch may vary depending on the actual usage conditions and may differ from the certified accuracy.

For details, please refer to Grand Seiko’s Certificate and Inspection Process.(under construction)

Can I get my Grand Seiko Standard Inspection Certificate reissued?

The Grand Seiko Standard Inspection Certificate cannot be reissued.

How accurate is Grand Seiko?

The accuracy of Grand Seiko differs according to the mechanism and caliber of your watch. For details on your watch, please refer to the instruction that came with your watch at the time of purchase.

Guidelines for the accuracy of Grand Seiko while in use:

QUARTZ : The annual accuracy is ±10 seconds when worn on the wrist within a normal temperature range (between 5 ºC and 35 ºC) for approximately 8 hours per day.

SPRING DRIVE : Average monthly loss / gain is ±15 seconds when worn on the wrist within a normal temperature range (between 5 ºC and 35 ºC）.

MECHANICAL : Accuracy of Grand Seiko mechanical watches when worn is specified within the target range of -1 to +10 seconds per day. To properly judge the accuracy under normal use conditions, check the mean value of gain / loss over a period of seven to ten days.

For information on general factors that affect accuracy of mechanical watches, please refer to "Accuracy of mechanical watches."

What is the accuracy of the mechanical watch in use / the mechanical watch movement at rest?

The accuracy of mechanical watches varies slightly from day to day, depending on various conditions. Therefore, the loss / gain of mechanical watches is not measured by a daily rate, but by an average daily rate over a period of 7 to 10 days. For this reason, the accuracy of mechanical watches is indicated by "the mean daily rate."

The accuracy of the mechnical watch in use

The accuracy of a mechanical watch varies slightly depending on individual user conditions such as winding state of the mainspring due to movement of the users’ arm, ambient temperature, and posture (direction of the watch). Accordingly, actual accuracy of a watch in use may differ from specifications in the "Grand Seiko Standard."