Compliance Manager

Compliance Manager is a tool that has been created by Microsoft to assist with their products and various compliance checks including GDPR and ISO standards. The compliance manager tool includes a list of checks that has been completed by Microsoft and all of the relevant information and a list of checks that should be completed by the customer. Within the tool you can assign tasks to users within the Office365 platform, create due dates, update statues and upload documents. This tool is very useful for any large organisations looking to comply with GDPR and ISO but will be overkill for smaller organisations due to the level of detail within it.
Office365 Security & Compliance
One of the key tools for Office365 and GDPR Compliance is the Security & Compliance area within Office365 has a number of tools that can assist with GDPR including a newly added GDPR Toolbox.

Within the Security & Compliance section of Office365 a set of tools allow you to classify data in SharePoint Online, OneDrive & Exchange either manually or automatically based on keywords that you can define or there are some built in rules that you can utilise i.e. detecting National Insurance Numbers of Debit Card Numbers. Labels can be created within the platform and criteria such as Retention & Automatic Deletion can be configured.
These tools allow you to easily classify data that is being stored within Office365 and then retain or delete that data automatically on a time period you can define. There are some functions that allow you to specify rules for Data Loss Prevention.