“21. In a sense a tension exists between these two sections. On its face, section 49 might be thought to confer an unrestricted power to reopen assessments by means of a late appeal. Section 33, by contrast, is limited in its application, both by the six year limit stipulated in subsection (1) and by the exclusion for generally prevailing practice contained in to the proviso to subsection (2). If section 49 is unlimited in its application, however, it provides an obvious route to circumvent the restrictions in section 33. That might be thought contrary to the statutory scheme. A similar point can be made in relation to section 29, dealing with discovery assessments, which is subject to a broadly similar limitation for generally prevailing practice. This difficulty arises, I suspect, because the assessment and appeal provisions that are not contained in theTaxes Management Act 1970 have their origins in a number of different Finance Acts, passed over a long period, and no attempt has been made to develop them into a coherent code using systematic concepts and terminology. It must be said that on the whole the assessment mechanism seems to work well in practice, but this is no doubt due to the good sense of Inspectors of Taxes and tax advisers rather than the coherence of the statutory provisions. In the present case, however, I have come to the opinion that the tensions are more apparent than real. They can readily be resolved by a proper analysis of section 49(1), and I now turn to that analysis. 22. Section 49 is a provision that is designed to permit appeals out of time. As such, it should in my opinion be viewed in the same context as other provisions designed to allow legal proceedings to be brought even though a time limit has expired. The central feature of such provisions is that they are exceptional in nature; the normal case is covered by the time limit, and particular reasons must be shown for disregarding that limit. The limit must be regarded as the judgment of the legislature as to the appropriate time within which proceedings must be brought in the normal case, and particular reasons must be shown if a claimant or appellant is to raise proceedings, or institute an appeal, beyond the period chosen by Parliament. 23. Certain considerations are typically relevant to the question of whether proceedings should be allowed beyond a time limit. In relation to a late appeal of the sort contemplated by section 49, these include the following; it need hardly be added that the list is not intended to be comprehensive. First is there a reasonable excuse for not observing the time limit, for example because the appellant was not aware and could not with reasonable diligence have become aware that there were grounds for an appeal? If the delay is in part caused by the actings of the Revenue, that could be a very significant factor in deciding that there is a reasonable excuse. Secondly, once the excuse has ceased to operate, for example because the appellant became aware of the possibility of an appeal, have matters proceeded with reasonable expedition? Thirdly, is there prejudice to one or other party if a late appeal is allowed to proceed, or if it is refused? Fourthly, are there considerations affecting the public interest if the appeal is allowed to proceed, or if permission is refused? The public interest may give rise to a number of issues. One is the policy of finality in litigation and other proceedings; matters have to be brought to a conclusion within a reasonable time, without the possibility of being reopened. That may be a reason for refusing leave to appeal where there has been a very long delay. A second issue is the effect that the instant proceedings might have on other legal proceedings that have been concluded in the past; if an appeal is allowed to proceed in one case, it may have implications for other cases that have long since been concluded. This is essentially the policy that underlies the proviso tosection 33(2) of the Taxes Management Act . A third issue is the policy that it is to be discerned in other provisions of the Taxes Acts; that policy has been enacted by Parliament, and it should be respected in any decision as to whether an appeal should be allowed to proceed late. Fifthly, has the delay affected the quality of the evidence that is available? In this connection, documents may have been lost, or witnesses may have forgotten details of what happened many years before. If there is a serious deterioration in the availability of evidence, that has a significant impact on the quality of justice that is possible and may of itself provide a reason for refusing leave to appeal late. 24. Because the granting of leave to bring an appeal or other proceedings late is an exception to the norm, the decision as to whether they should be granted is typically discretionary in nature. Indeed, in view of the range of considerations that are typically relevant to the question, it is difficult to see how an element of discretion can be avoided. Those considerations will often conflict with one another, for example in a case where there is reasonable excuse for failure to bring proceedings and clear prejudice to the applicant for leave but substantial quantities of documents have been lost with the passage of time. In such a case the person or body charged with the decision as to whether leave should be granted must weigh the conflicting considerations and decide where the balance lies.”