GOV.UK
Working the examination: Making initial or revised decisions / amending or terminating awards without first issuing formal information notices
You are not obliged to issue a formal information notice under S14(2), 15(2) or 16(3) before making an initial (S14(1)) or revised (S15(1)) decision or before deciding to amend or terminate the award (S16(2)). In all these instances, the statute says you may give a notice; but the power to decide / amend / terminate is free standing and does not depend on the issue of the information notice. See CCM5260 for the factors you should consider when deciding whether to amend or terminate the award or to issue a formal information notice.
In most cases you will not follow up your informal request with a formal information notice before taking any decision on the award.