Third-party suppliers can have an important influence on your business. Both from an economic and a security point of view. In this context, it is important to create standard procedures to follow in case you need to terminate your business relationship with one of them.
Remember to keep track of all the information you have shared with the third party, with sharing date, level of access provided and amount of data sent or received. Then create replicas of everything you receive (in accordance with the signed legal contract) and keep these copies securely stored within your infrastructure. Finally, include a withdrawal section in the contract you submit to your suppliers.