IEIM102100 - Exchange of information: Types of exchange: On request
Exchange on request is the baseline of exchange of information, under which a Competent Authority (IEIM101400) of one tax authority contacts the Competent Authority of another tax authority to ask for information pertaining to a customer or group of customers. All exchange instruments allow for exchange on request.
The OECD has set a minimum standard for exchange on request: broadly, this requires that the tax authority must be able to provide the information from its own records, or if necessary obtain it using information powers. Information powers in this context are those equivalent to Schedule 36 to FA08. It is not guaranteed that another tax authority will have any other powers beyond those. See IEIM101500 for how reciprocity works under exchange instruments.
There is detailed guidance on exchange on request in IEIM111000+.