How to find your Secret ID (SID) in Pokémon
Your game shows a six-digit Trainer ID and never shows your Secret ID. There is no menu for it in Scarlet & Violet, Sword & Shield or Legends: Z-A. The fastest way to learn it: trade anything with the Vending Machine, which reads your trainer details when it connects and shows them to you. The free Mystery Egg you get for joining the email list counts, so it can cost nothing.
What are a Trainer ID and a Secret ID?
When you start a new save, the game draws one 32-bit number. Its last six digits are shown to you as your Trainer ID. The remaining four digits are your Secret ID, and the game keeps them to itself. That has been the system since Pokémon Sun and Moon, and it is the same in Scarlet & Violet, Sword & Shield and Legends: Z-A.
Together they identify your save file. The game uses the pair, with the Pokémon’s own hidden values, to decide whether a Pokémon is shiny, and to decide whether a Pokémon is yours or an outsider (traded in from another trainer).
Why would I want my SID?
For a Custom Build with your own trainer details. Give the machine your trainer name, Trainer ID and Secret ID, and the Pokémon it delivers is written as if you were its Original Trainer: you can nickname it, and it does not get the outsider EXP boost. Without the SID, the Pokémon still arrives and works normally; it simply shows another trainer as its Original Trainer.
Only a Pokémon’s Original Trainer can rename it. With your details on it, that is you.
Traded Pokémon gain extra EXP. One written as yours levels like one you caught.
Some event-only Pokémon have fixed trainer details that cannot be changed without making them invalid. The order note tells you if that applies.
The three ways to learn your SID
Nothing in the game shows it, and Pokémon HOME does not show it either. Online IV calculators cannot reveal it: they never see the numbers that matter. That leaves two real methods, and one of them can be free.
Claim the free Mystery Egg from the email sign-up, or order any item from $1.99. Enter the Link Trade code and the machine shows your TID and SID the moment it connects. Takes about two minutes.
Tools like PKHeX can read it from your save file, but that needs a modified console. We do not recommend or support it.
Anyone with a save editor who receives a Pokémon you caught can read your IDs off it. Same tools, same catch.
Get your SID from the Vending Machine
Claim the free egg, or order anything small
The free Mystery Egg from the email sign-up is a real order, so it works. So does any item from the game you play. Your order page shows a private Link Trade code straight away.
Enter the code in-game
Start a Link Trade with that code when the order page says the machine is searching.
Read it off the prompt
The order page shows the line below. It is also saved to your order notes, so you can find it again later.
Found Link Trade partner: YourName. TID: 123456 SID: 4242. If this isn’t you, tap Cancel now.
The line is saved to your order as a note the moment it is sent, so it is still there on My Orders after the trade, and the store emails it to you as a note on your order.
SID questions
Yes. It is not a password or an account credential. Anyone you trade with can read it, and it cannot be used to sign in to anything or access your save. It only matters for how a Pokémon's origin is written.
No. Trainer ID and Secret ID are fixed for a save file. Start a new game and you get a new pair.
No. Ready-made Pokémon and Mystery Pokémon arrive with the Original Trainer NinVendor. You only need it if you want a Custom Build with your own trainer details.
Learn your SID in about two minutes.
Claim the free Mystery Egg from the email sign-up, or pick any item from your game. The Vending Machine shows your Trainer ID and Secret ID the moment it connects, and you can use them on any Custom Build afterwards.