4. Comparison table: Pre-action discovery, non-party discovery and Norwich Pharmacal order

When used 

Against whom 

Main purpose 

Key limit 

Before proceedings 

Often before proceedings 

To obtain directly relevant documents before deciding or formulating a claim 

Documents must be directly relevant. Not for fishing. Applicant must show necessity, sufficient identification of documents/classes, possession, custody or power, and likely future proceedings. 

Non-party discovery 

After proceedings have begun 

A non-party 

To obtain relevant documents needed in existing proceedings 

The broader Peruvian Guano test applies, but the order must still be necessary for fair disposal or saving costs. Request must be proportionate, focused, not oppressive, and subject to privilege/confidentiality safeguards. 

Norwich Pharmacal order 

Often before proceedings 

A person mixed up in wrongdoing, often innocently 

To identify a wrongdoer or obtain information needed to bring a claim 

Exceptional equitable remedy. Not a general investigative tool. Court balances necessity, proportionality, confidentiality, privacy, privilege and costs. Applicant usually pays reasonable compliance costs.