>_ FAQ: Serial Numbers, Series by Series

All known Nintendo Switch serial number prefixes, what they mean, and real-world examples of full numbers with their corresponding verdict. A serial number can be found under the console, to the left of the USB port, or in System Settings → Console → Serial Numbers. If the verdict is favorable, the next steps involve your microSD card and the Atmosphère patch.

3 letters + 1 digit

The relevant prefix is 4 characters long: the 3 letters indicate the model and region, while the digit indicates the production wave (1, 4, or 7 for the first Switch units).

10 digits after

The 10 digits follow the manufacturing order. The smaller the number, the older the console—and the more likely it has the bootrom vulnerability.

Beware of Mix-ups

On the sticker, the digit 0 can look like the letter O, and 1 like I. After the prefix, there are always digits: never letters.

Official Ranges, Identical to the Checker

This table is generated from the same data as the checker: the ranges shown here are the exact ones used to determine a verdict. The comparison is based on the 10 digits that follow the prefix.

Prefix	Unpatched	Potentially Patched	Patched

Last range revision: September 6, 2026. The prefixes of the most recent revisions (XKW, XKJ, XJW, XJJ, XTW, XTJ, XWW, XWJ) are patched by design: no serial number in these series is vulnerable.

"Erista" Series — 2017-2018 Switch

These are the only consoles affected by the bootrom vulnerability. Depending on the serial number, the console is either unpatched, potentially patched, or already patched.

Prefix	Series / Region	Real Example	Expected Verdict
XAW1	Launch March 2017 — Europe / Americas	`XAW10032500000`	Unpatched
XAW4	Late 2017 → 2018 — Europe / Americas	`XAW40010999999`	Unpatched
XAW4	Late 2017 → 2018 — Europe / Americas	`XAW40011500000`	Potentially Patched
XAW7	2018 — Europe / Americas	`XAW70017500000`	Unpatched
XAW7	2018 — Europe / Americas	`XAW70035000000`	Patched
XAJ1	Launch 2017 — Japan	`XAJ10015000000`	Unpatched
XAJ4	Late 2017 → 2018 — Japan	`XAJ40045999999`	Unpatched
XAJ4	Late 2017 → 2018 — Japan	`XAJ40048153719`	Potentially Patched
XAJ4	Late 2017 → 2018 — Japan	`XAJ40060000000`	Patched
XAJ7	2018 — Japan	`XAJ70039999999`	Unpatched
XAJ7	2018 — Japan	`XAJ70041000000`	Potentially Patched

Paste any of these numbers into the checker: it will display the verdict, the exact range for the series, and the certainty level.

"Mariko" Series — Always Patched

Starting with the 2019 revision, the vulnerability is fixed in the silicon. No serial number in these series is exploitable: only a modchip can still run unsigned code.

Prefix	Model	Real Example	Verdict
XKW	Switch V2 2019, improved battery life — Europe / Americas	`XKW10012345678`	Patched
XKJ	Switch V2 2019 — Japan	`XKJ10020000000`	Patched
XJW	Switch Lite — Europe / Americas	`XJW10008500000`	Patched
XJJ	Switch Lite — Japan	`XJJ10004200000`	Patched
XTW	Switch OLED — Europe / Americas	`XTW10001234567`	Patched
XTJ	Switch OLED — Japan	`XTJ10002000000`	Patched
XWW / XWJ	More recent revisions	`XWW10000123456`	Patched

Frequently Asked Questions

My prefix isn't on the list, what should I do? First, double-check the sticker (0/O and 1/I). If it's correct, consider the console untested: the checker will refuse to give a verdict, and only a real-world test can determine its status.
Two consoles bought on the same day, but two different verdicts? This is normal: stores sell through different manufacturing batches over several months.
The box shows a different serial number than the console. Only the number on the console itself matters: boxes can sometimes be swapped in stores or during repairs.
Does a warranty replacement change the verdict? Yes. A replaced console will have a new serial number, often from a much more recent—and therefore patched—batch.
Can a system update patch my console? No. The fix is burned into the chip during manufacturing; no update or downgrade can change it.
What about the Switch 2? It's entirely different hardware and is unrelated to this vulnerability: nothing described here applies to it.

Sources consulted on September 6, 2026: Switch Hackable Serial List · switch.hacks.guide · Hackintendo