Hi,
If the company has insurance and charges the workers for it, and this is in connection with the worker’s employment, it will always reduce pay for minimum wage purposes. If the liability for the insurance belongs to the employer, and the employer is passing that cost on to the worker, any deductions made in respect of this will also reduce pay for minimum wage purposes.
It will not affect pay if the worker makes the decision to take up their own insurance as a payment from the worker to a third party, and there is no requirement by the employer for the worker to do so. If the liability for the insurance sits with the worker, and the employer does not require this as part of the role, then it will not reduce pay for minimum wage purposes.
You can see more information on deductions and payments here:
Calculating the minimum wage
Thank you.