Hi, can someone please tell me where I can find out about the certifications / insurance that QuickBooks itself holds - PI Cover, ISO 9001 etc

Hello tracey2972, thanks for posting on the Community.

The QuickBooks Online Database is ISO/IEC 27001:2013 certified and QuickBooks Online is assessed annually for PCI DSS compliance. 

For further information on how we're handling data, please see our GDPR centre and data processing agreement.