Certain customers allow you to have non ISO 9001 certified suppliers
Check your customer CSRs-- these do not have to be individually approved suppliers:
Ford:
Sub-tier supplier quality management system requirements
• Where a sub-tier supplier is not third party certified to ISO/TS 16949, Ford reserves the right to require the organization to ensure sub-tier supplier
compliance with the “Minimum Automotive Quality Management System Requirements for Sub-tier Suppliers” available through
• Where any organization has sub-tier suppliers not third party certified to ISO/TS 16949, the organization is encouraged to require sub-tier supplier
compliance with the “Minimum Automotive Quality Management System Requirements for Sub-tier Suppliers”.
GM
When a supplier to an organization is so small as to not have adequate resources to develop a system according to IATF 16949:2016 or ISO 9001:2015, certain specified elements may be waived by the organization. The organization shall have decision criteria for determining “specially designated small suppliers”. Such decision criteria shall be in writing and applied consistently in the application of this provision. The existence and use of such decision criteria shall be verified by 3rd party auditors.
NOTE 1: ISO 9001:2015 and IATF 16949:2016 Minimum Automotive Quality Management System Requirements for Sub-Tier Suppliers contain fundamental quality management system requirements of value to any size of provider of production materials, production, service, and accessory parts, or heat treating, plating, painting or other finishing services. There are a number of methods to implement a compliant system, so it is recognized that a simpler Quality Management System approach could be used for the smaller suppliers of organizations to which IATF 16949:2016 clause 8.4.2.3 applies.
NOTE 2: “Small” may also refer to volume supplied to automotive.
All the reasons that others have given are excuses and could be used to mitigate from a major to a minor but none would be acceptable as per the standards as this says shall
Using a risk-based model, the organization shall define a minimum acceptable level of QMS development and a target QMS development level for each supplier.
Unless otherwise authorized by the customer a QMS certified to ISO 9001 is the initial minimum acceptable level of development. Based on current performance and the potential risk to the customer, the objective is to move suppliers through the following QMS development
progression: