What is a FIP?

FIP is any entity that has financial information of a Person and provides the same within the framework of the applicable regulation

Can an entity consume data but not share data. Can it be just an FIU and not a FIP?

As per the principle of reciprocity, the entity needs to be a FIP first and then an FIU. Examples include issuer/acquirer in UPI or a bank must report to then access credit bureau data.

Assuming the FIP has the data requested for, are they obligated to share it with the Account Aggregator? For e.g. FIU asks for 1 year of data, can FIP refuse to provide 1 year of data?

The FIP, if it has the requested data, is obligated to share the data.

What is the unique identifier used by FIPs for discoverability? Is the unique identifier standardised across all Banks?

The identifier is specific to the requirements of the FIP like verified Mobile Number, PAN, Account no., FIP Customer ID etc.