Instance Method


Assesses whether authentication can proceed for a given policy.


- (BOOL)canEvaluatePolicy:(LAPolicy)policy error:(NSError * _Nullable *)error;



The policy to evaluate. For possible values, see LAPolicy.


If the method fails, it uses this parameter to return an error detailing what went wrong. See LAError for possible error codes.

Specify nil for this parameter to ignore any errors.

Return Value

YES if the policy can be evaluated, otherwise NO.


Some policies impose requirements that must be met before authentication can proceed. For example, a policy that requires biometrics can’t authenticate if Touch ID or Face ID is disabled. This method tests all the prerequisites for a given policy.

Don’t store the return value from this method because it might change as a result of changes in the system. For example, a user might disable Touch ID after you call this method. However, the reported value does remain consistent until your app enters the background.

See Also

Checking Availability


The set of available local authentication policies.


The type of biometric authentication supported by the device.


The set of available biometric authentication types.