What the error means
Error processing Instruction N: custom program error: 0x3
The token account passed in holds a different token than the mint in the instruction, usually because an app mixed up two token accounts.
| Where it comes from | SPL Token program |
| Code | 3 (0x3) MintMismatch |
How to fix it
- Check the mint of each token account in the explorer.
- Refresh the app so it reloads your accounts, then retry.
- When building transactions, derive the associated token account from the correct mint and owner.
If that is not it
- If the token is Token-2022, make sure the instruction uses the Token-2022 program, not the original Token program.
More fixes: how to decode any Solana error code and why Solana transactions fail.
Source
Error text and code from SPL Token program error definitions (solana-program/token), read on 24 October 2026.