Is written procedure required for internal Audit if audit is outsourced to outside consultant?

Yes, it is stated in the requirement 8.2.4 Internal audit that the organization must document a procedure that describes the responsibilities and requirements for planning and conducting audits and all necessary reports. Therefore, in your procedure you will describe that you have an outsourced internal audit process, you will describe which criteria that company has to have, how will you communicate with them, how will you plan the internal audits, how consultant company will give you reports, and so on. To summerise, this procedure needs to have all the elements requested by the standard and needs to prove how will you have this process under control. Remember, that no matter that you have outsourced this process, it is your responsibility for it.

The following articles can be of help:

• Five main steps in the ISO 13485:2016 internal audit https://advisera.com/13485academy/knowledgebase/five-main-steps-in-the-iso-134852016-internal-audit/
• How to create a checklist for an ISO 13485 internal audit for your QMS https://advisera.com/13485academy/knowledgebase/how-to-create-a-checklist-for-an-iso-13485-internal-audit-for-your-qms/

You can also see how ISO 13485:2016 Internal Audit Toolkit looks like here: https://advisera.com/13485academy/iso-13485-internal-audit-toolkit/