> ## Documentation Index
> Fetch the complete documentation index at: https://base-a060aa97-docs-add-b20-spec.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# IB20.policyId

> Generated B20 reference for policyId(bytes32).

[Related concept](/base-chain/specs/upgrades/beryl/b20/specification/concepts/policies-and-scopes)

## Signature

```solidity theme={null}
function policyId(bytes32 policyScope) external view returns (uint64);
```

| Field               | Value               |
| ------------------- | ------------------- |
| Selector            | `0xdb3de624`        |
| Canonical signature | `policyId(bytes32)` |

## Description

The current policy ID configured for `policyScope`. Returns `0` (always-allow built-in)
for any slot that has never been assigned.
Dev: Reverts with `UnsupportedPolicyType` when `policyScope` is not recognized by this token.
Param: policyScope Policy slot scope.
Return: Configured policy ID.

## Access control

Read-only or ERC-20-standard access rules unless the NatSpec states otherwise.

## Policy interaction

Reads or writes a token policy-scope pointer into the PolicyRegistry.

## Example

```solidity theme={null}
uint64 id = IB20(token).policyId(B20Constants.MINT_RECEIVER_POLICY);
```

## Related

* [IB20 reference](/base-chain/specs/upgrades/beryl/b20/specification/reference/interfaces/IB20)
* [Constants & addresses](/base-chain/specs/upgrades/beryl/b20/specification/reference/constants-and-addresses)