If you've incorrectly claimed free NHS prescription items when you did not hold a valid exemption in place, you may be issued with a Penalty Charge Notice (PCN).
There's a duty of care when claiming help with NHS charges.
It's expected a patient or a patient's representative will read the declaration before signing and only sign it if it's true. It's their responsibility for this declaration.
The declaration on an NHS prescription states 'I declare that the information I have given on this form is correct and complete. I understand that if it is not, appropriate action may be taken. I confirm proper entitlement to exemption. To enable the NHS to check I have a valid exemption and to prevent and detect fraud and incorrectness, I consent to the disclosure of relevant information form this form to and by the NHS Business Services Authority the Department for Work and Pensions and Local Authorities.'
As you've signed the prescription form to confirm your exemption to be correct and this is found to be false, the prescription charge and penalty charge would be correct and you would liable for the charges.