generated: '2026-07-21'
method: searched
source: https://docs.toucan.earth/developers/support/error-codes
format: contract-error-codes
description: >-
  Toucan uses custom numeric error codes (not Solidity custom errors) in its pool
  contracts to keep contract size small. Codes are returned by carbon pool and
  Cross-Chain Bridge (COB) contract operations.
envelope: numeric error code emitted by pool / COB smart contracts
error_codes:
  - code: 1
    description: User is not authorized
  - code: 2
    description: Empty array provided as input
  - code: 3
    description: Pool is full of TCO2s
  - code: 4
    description: ERC20 is blacklisted in the pool (e.g. blacklisted TCO2s like the HFC-23 project)
  - code: 5
    description: ERC20 is not whitelisted in the pool (non-TCO2 ERC20s must be manually whitelisted)
  - code: 6
    description: Vintage start time of a TCO2 is too old
  - code: 7
    description: Region is not accepted in the pool
  - code: 8
    description: Standard is not accepted in the pool
  - code: 9
    description: Methodology is not accepted in the pool
  - code: 10
    description: Provided fee is invalid, not in a basis points format [0,10000)
  - code: 11
    description: Provided address needs to be non-zero
  - code: 12
    description: Validation check to ensure array lengths match
  - code: 13
    description: TCO2 not exempted from redeem fees
  - code: 14
    description: The pool is paused
  - code: 15
    description: Redemption transaction has leftover unredeemed value; all value must be redeemed
  - code: 16
    description: Redemption exceeds deposited TCO2 supply
  - code: 17
    description: User must be a router
  - code: 18
    description: User must be the pool owner
  - code: 19
    description: Zero destination address is invalid for pool token transfers
  - code: 20
    description: Self destination address is invalid for pool token transfers
  - code: 21
    description: Zero amount provided as an input (e.g. in redemptions) is invalid
  - code: 22
    description: ERC20 is not eligible to be pooled
  - code: 23
    description: Carbon registry is already supported in COB
  - code: 24
    description: The caller is not granted the VERIFIER_ROLE in COB
  - code: 25
    description: The caller does not own the provided batch
  - code: 26
    description: The caller is not a valid batch owner (not a TCO2 contract or verifier)
  - code: 27
    description: The batch is not in Confirmed status
  - code: 28
    description: The batch is not in a requested status (DetokenizationRequested or RetirementRequested)
  - code: 29
    description: The batch does not exist
  - code: 30
    description: The batch has an invalid status based on the action requested
  - code: 31
    description: The batch is missing an associated project vintage
  - code: 32
    description: The serial number in the batch is already approved
  - code: 33
    description: The batch is not in Pending status
  - code: 34
    description: The batch is already fractionalized
  - code: 35
    description: The batch is not in Rejected status
  - code: 36
    description: The project vintage is already set in the batch
  - code: 37
    description: The transfer is not approved
  - code: 38
    description: The COB contract is paused
  - code: 39
    description: The caller is invalid
  - code: 40
    description: The TCO2 for the batch is not found
  - code: 41
    description: The registry for the provided vintage is not supported
  - code: 42
    description: No TCO2 was minted as part of tokenization
  - code: 43
    description: Only mints are supported for the batch contract to receive an NFT
  - code: 44
    description: New batch status is invalid
  - code: 45
    description: The TCO2 batch amount has a mismatch
  - code: 46
    description: The TCO2 batch amount approval has failed
  - code: 47
    description: The TCO2 batch not confirmed
  - code: 48
    description: The TCO2 batch not whitelisted
  - code: 49
    description: The TCO2 is non matching NFT
  - code: 50
    description: The TCO2 quantity in batch is higher than total vintages
  - code: 51
    description: The fee to be charged is too high
  - code: 52
    description: The max fee to be paid is invalid
  - code: 53
    description: The pool feature is not supported
  - code: 54
    description: The TCO2 decimals provided to retirement or detokenization requests are invalid
  - code: 55
    description: The TCO2 quantity in the batch is invalid
  - code: 56
    description: Splitting is required on detokenization/retirement finalization, but 2 new serial numbers were not provided
  - code: 57
    description: The score set for the ERC-1155 token in the pool is invalid
  - code: 58
    description: The score of the ERC-1155 token in the pool is not set
  - code: 59
    description: The underlying decimals are too high for the pool
  - code: 60
    description: The provided supply cap is invalid and should match the underlying token decimals (e.g. for an ERC-1155 token whose smallest denomination is tonnes, the pool supply cap should not include decimals of lower fidelity than tonnes)