How to Decode a Bosch Appliance Serial Number (FD Code, E-Nr, and the 800/500/300 Series)
Bosch (and Siemens, Thermador, Gaggenau) use a German convention: E-Nr = model number, FD = production date (Fertigungsdatum), Z-Nr = serial number. The FD is four digits: add 20 to the first two to get the year (drop leading 1 if ≥100), and the last two digits are the month. The 800/500/300 series in the model name are quality tiers — not date codes.
The Three Bosch Numbers Explained
Bosch appliances have three identifier fields on the label, each with a distinct purpose:
- E-Nr (Erzeugnisnummer): The model number — equivalent to a US "model number." Used to order parts and find manuals.
- FD (Fertigungsdatum): Production date — the field that encodes the manufacturing month and year. This is what you decode for appliance age.
- Z-Nr (Zähl-Nummer): The true sequential serial number — used for individual unit tracking.
Many people confuse the FD for the serial number. It is not — it is the production date code. The Z-Nr is the serial.
The FD Math (The +20 Rule)
The FD code is always four digits, formatted YYMM where YY is a two-digit year base and MM is the month:
- Take the first two digits of the FD
- Add 20
- If the result is ≥ 100, drop the leading "1"
- The result is the last two digits of the year (so 15 = 2015, 21 = 2021)
- The last two digits of the FD are the month (01–12)
Worked Examples
Example 1: FD 9512 → 95 + 20 = 115 → drop leading 1 → 15 → 2015. Month: 12 = December. December 2015.
Example 2: FD 0103 → 01 + 20 = 21 → 2021. Month: 03 = March. March 2021.
Example 3: FD 8107 → 81 + 20 = 101 → drop leading 1 → 01 → 2001. Month: 07 = July. July 2001.
Example 4 (Bosch dishwasher SHPM88Z75N): FD 950200451 → first four digits: 9502 → 95 + 20 = 115 → 2015, month 02 = February. February 2015.
Full 18-Digit Bosch Serial Breakdown
| Positions | Field | Example |
|---|---|---|
| 1–2 | Factory code | FD |
| 3–6 | FD production date (YYMM) | 9502 |
| 7–13 | Internal production code | 0045100 |
| 14–18 | Z-Nr daily sequential count | 00451 |
Bosch 800 / 500 / 300 Series: Quality Tiers, Not Dates
One of the most common misconceptions about Bosch dishwashers is that a higher series number means a newer unit. It does not. The series number is a quality tier within the current product lineup:
| Series | Sound level | Key features |
|---|---|---|
| 100 Series | ~50 dBA | Basic, no third rack |
| 300 Series | ~46 dBA | Third rack option, AquaStop |
| 500 Series | ~44 dBA | AutoAir drying, third rack standard |
| 800 Series | ~42 dBA | CrystalDry, MyWay third rack, PrecisionWash |
| Benchmark | ~38 dBA | Top tier, all features |
A Bosch 800 Series unit built in 2012 is older than a Bosch 300 Series built in 2022. For age, always use the FD code — never the series number.
Sub-Brands Using the Same Scheme
All brands under BSH Hausgeräte GmbH use the identical FD encoding system: Bosch, Siemens, Thermador, Gaggenau, Neff, and Balay. If you can find the FD code on a Thermador range, the +20 rule applies identically.