Paragraph 6
Where, upon a review of a decision rejecting a claim for pension, the Secretary of State makes an award on the basis that medical opinion has developed since the date of the decision which is the subject of the review, no payment shall be made in respect of any period preceding whichever is the later of—
the date on which the Secretary of State considers that medical opinion had developed to the extent that an award in the claimant's case was justified; and
the date three years before the date of application for a review or, where the review is instigated by the Secretary of State, the date three years before the date of the Secretary of State's review decision.
Where the Secretary of State accepts a claim and he is satisfied that the claimant would have made a claim at an earlier date but for advice he gave that a claim would be rejected on the basis of medical opinion, the Secretary of State may make payment in respect of a period commencing on, but not in respect of any period before, whichever is the later of—
the date on which the Secretary of State considers that medical opinion had developed to the extent that an award in the claimant's case was justified; and
the date three years before the date of claim.