Scottish Court of Session Decisions

University Court University Glasgow v. Commissioners Customs Excise [2003] ScotCS 38 (20 February 2003)

FIRST DIVISION, INNER HOUSE, COURT OF SESSION

Lord President Lord Marnoch Lord Hamilton

XA162/01 OPINION OF THE COURT delivered by LORD HAMILTON in APPEAL to THE COURT OF SESSION under The Tribunals and Inquiries Act 1992, section 11 by UNIVERSITY COURT OF THE UNIVERSITY OF GLASGOW Appellant; against COMMISSIONERS OF CUSTOMS AND EXCISE Respondents; against A decision of the Edinburgh VAT and Duties Tribunal dated 23 August 2001 and communicated to the Appellant on the same date. _______

 

Act: Ghosh; Dundas & Wilson, C.S (for the Appellants)

Alt: Young; Shepherd & Wedderburn (for the Respondents)

20 February 2003

1. Over various accounting periods arrangements were in place among (1) the appellant, (2) Gilmore Leasing Limited ("GL"), a member of the University VAT Group, and (3) Gilmorehill Leaseco (1996) Ltd ("GL 1996"), not a member of that Group, which involved the purchase, hire and sale of certain assets. Questions have arisen concerning the VAT liability (if any) of the appellant for supplies made in furtherance of these arrangements. The merits of the respondents' claim for tax have not yet been considered by a tribunal. A preliminary question has, however, arisen concerning the competency of the procedure adopted by the respondents in assessing the appellant to tax. Four conjoined appeals were heard by a VAT and duties tribunal (constituted by Mr. T.G. Coutts, Q.C., Chairman, sitting alone), in three of which the issue of competency arose. It is, subject to one additional matter, sufficient for present purposes to summarise the circumstances pertinent to one of these appeals [EDN/01/28], which relates to the assessment period ended January 1998.
2. On 30 January 2001 an officer of the respondents wrote to the appellant's Director of Finance a letter under the heading "ASSESSMENTS FOR THE PERIOD 01/98". The first paragraph of that letter ran -

"1. I enclose assessments for the University for the period 01/98. There are two types of assessment:

(a) the preferred assessment (based on the disallowance of input tax on the

grounds that it is attributable to exempt supplies);

(b) the alternative assessment (based on the disallowance of input tax on the grounds that there has been an abuse of the law)".

There followed a narrative of the purchase, hire and sale arrangements. Paragraphs 3 and 4 were in the following terms:-

"3. The legal background to the assessments is as follows.

4. The preferred assessment. This assessment is based on the evidence obtained to date (including the additional information provided at the meeting we had on 19 December 2000) regarding the VAT Group's intended use of the assets in question at the time that they were acquired. In the Commissioners' view, that evidence indicates that the input tax claimed by the VAT Group in respect of these assets is not, as you contend, attributable exclusively to taxable supplies, but rather should be treated as attributable to taxable and exempt supplies and the related input tax recovered only to the extent allowed by your partial exemption method.".

Paragraphs 5, 6 and 7 expanded on the legal reasoning on which the preferred assessment proceeded. Paragraph 8 was in the following terms:-

"The preferred assessment has been calculated as follows:

Input tax wrongly claimed in full on "Equipment Leasing" = £128,508

Input tax allowed as part of PE "Pot" £128,508 x 13.33% = (£ 17,131)

NET VAT UNDERDECLARED - 01/98 £111,377"

Paragraphs 9, 10 and 11 read as follows:-

"9. The alternative assessment. This assessment is based on the Commissioners' view that, based on the information provided to date, we can see no commercial advantage in inserting GL and GL (1996) into the supply chain. We, therefore, now think it likely that the insertion of GL and GL (1996) into the supply chain was entered into solely to avoid suffering irrecoverable VAT. On this basis, the Commissioners consider that there has been an abuse of the law, and the input tax claims of the University and GL in respect of the goods which form part of the leasing arrangements are incorrect.

10. The interpretation of the VAT legislation which leads the Commissioners to conclude that there has been an abuse of law is set out in my letter of 30 October 2000.

11. The alternative assessment has been calculated as follows:-

Input tax wrongly claimed in full "Equipment Leasing" = £128,508

Input tax allowed as part of PE "Pot" £128,508 x 13.33% = (£17,131)

Output tax wrongly charged to GL (1996) = (£17,554)

Input tax wrongly claimed on invoices from GL (1996):

£18,247 x 13.33% = £ 2,432

NET VAT UNDERDECLARED - 01/98 = £96,255"

The writer then asked the addressee to note that both of these assessments had been issued at that time to protect the Commissioners' position in view of impending time limits for assessment. The possibility that the Commissioners might wish to see additional documents, including tax planning documents, was mentioned and a request was made that certain specific documents, previously requested, be produced.

3. Paragraphs 16, 17 and 18 read:-

"16. Please note that the preferred assessment and the alternative assessment are mutually exclusive. You only have to pay one type of assessment. You should pay the preferred assessment. If it turns out that the preferred assessment is wrong, but the alternative assessment is correct, I will make the appropriate adjustments.

17. If you do not pay the preferred assessment within 30 days, further interest will be charged.

18. Finally, you have the right to appeal to the VAT and Duties Tribunal against either or both of the assessments".

4. Enclosed with that letter were two documents, each headed "NOTICE OF ASSESSMENT" and addressed to the appellant. One of these, headed "PREFERRED ASSESSMENT" specified the sum of tax calculated under the preferred assessment referred to in the letter, together with a calculation of interest on that tax. The other, headed "ALTERNATIVE ASSESSMENT", specified the sum of tax calculated under the alternative assessment there referred to, together with a calculation of interest on that tax. Each contained the statement -

"You are hereby assessed for VAT and interest, as set out above. The reasons behind the assessment are set out in a covering letter".

5. The additional matter referred to above is as follows. Another of the conjoined appeals (EDN/01/91) concerned assessments raised for periods of assessment ended 07/98 to 07/00. There "preferred assessments" and "alternative assessments" were again notified but the covering letter explained that the alternative assessments themselves proceeded upon two separate legal bases, the first being an alleged "abuse of law", under reference to an interpretation of UK legislation, and the other, described as a "last resort" contention, being an alleged "abuse of right" under reference to a principle evolved under Community law. In relation to each period the calculation of tax and the tax assessed on the preferred assessment were different from the relative calculation and tax on the alternative assessment; but the calculation of tax and the tax assessed on each of the legal bases for the alternative assessment were the same.
6. The sole issue with which the appeal to this court is concerned is the competency of the Commissioners making and notifying, in respect of the same transaction or series of transactions in one or more accounting periods, separate (distinct) assessments for VAT on an alternative basis. The VAT and duties tribunal held that such procedure was competent.
7. Mr. Ghosh for the appellant, in a lucid and attractive presentation, submitted that the Commissioners had no power to proceed as they had done. He advanced the following propositions. The making of multiple assessments (including alternative assessments) gave rise to multiple liability to tax. It had the result that tax on each assessment would require to be paid as a precondition of appealing. None of this could have been Parliament's intention. The difficulties were not cured by the existence of any administrative discretion vested in the Commissioners. There was no proper analogy with alternative assessments in respect of direct taxes. The making of alternative assessments was not an assessment made "to the best of [the Commissioners'] judgment"; it was ultra vires. The Commissioners were not prejudiced by being unable to issue alternative assessments, as they could incorporate within any single assessment alternative bases (of fact and/or of law) on which the assessment was made.
8. At this point it is appropriate to notice the relevant provisions of the Value Added Tax 1994 (as amended)("the 1994 Act"). Section 73, in so far as material, provides as follows:-

"(1) Where a person has failed to make any returns required under this Act (or under any provision repealed by this Act) or to keep any documents and afford the facilities necessary to verify such returns or where it appears to the Commissioners that such returns are incomplete or incorrect, they may assess the amount of VAT due from him to the best of their judgment and notify it to him.

(2) In any case where, for any prescribed accounting period, there has been paid or credited to any person -

(a) as being a repayment or refund of VAT, or

(b) as being due to him as a VAT credit,

an amount which ought not to have been so paid or credited, or which would not have been so paid or credited had the facts been known or been as they later turn out to be, the Commissioners may assess that amount as being VAT due from him for that period and notify it to him accordingly.

...

(4) Where a person is assessed under subsections (1) and (2) above in respect of the same prescribed accounting period the assessments may be combined and notified to him as one assessment.

...

(9) Where an amount has been assessed and notified to any person under subsection (1), (2) ... above it shall, subject to the provisions of this Act as to appeals, be deemed to be an amount of VAT due from him and may be recovered accordingly, unless, or except to the extent that, the assessment has subsequently been withdrawn or reduced".

9. Section 83 provides that, subject to section 84, an appeal shall lie to a tribunal with respect to various matters including -

"(p) an assessment -

(i) under section 73(1) or (2) in respect of a period for which the

appellant has made a return under this Act;

...

or the amount of such an assessment".

Section 84(3) provides:-

"Where the appeal is against a decision with respect to any of the matters mentioned in section 83 ... (p) ... it shall not be entertained unless -

(a) the amount which the Commissioners have determined to be payable

as VAT has been paid or deposited with them; or

(b) on being satisfied that the appellant would otherwise suffer hardship

the Commissioners agree or the tribunal decides that it should be entertained notwithstanding that that amount has not been so paid or deposited".

10. Section 58 provides that Schedule 11 shall have effect. Paragraph 1(1) of that Schedule provides "VAT shall be under the care and management of the Commissioners".
11. In developing his submissions Mr. Ghosh noted that it was in the first instance for a taxable person to account for and pay VAT in respect of supplies made by him (the 1994 Act, section 25(1) and the relative Regulations). Section 73(1) empowered the Commissioners to assess the amount of tax due from such a person essentially in circumstances where something had gone wrong with the self accounting and payment requirement. Section 73(2) was concerned with overpayment, and section 73(4) conferred a power to make a combined assessment when both subsections (1) and (2) applied. Had Parliament intended to authorise alternative assessments an express provision at this point might have been expected. The deeming provision in section 73(9) had the effect that each assessment made and notified under section 73(1) created a liability in debt due by the assessed person. If two or more assessments, albeit expressed in the alternative, were made and notified in respect of the same transaction, prima facie the amount due was the aggregate of the amounts assessed. The fact that recovery was discretionary ("and may be recovered accordingly") in the exercise of the Commissioners' care and management of VAT (Schedule 11, para. 1(1)) did not detract from the liability being in the aggregate. The statute should not be construed so that a person was dependent on initiating judicial review procedure to prevent recovery from him of the aggregate sum. If alternative assessments were competent, the effect of making them was to create a double liability. That cannot have been the intention of Parliament. Likewise, the effect of making and notifying two or more assessments, albeit expressed in the alternative, would, if lawful, have the effect that an appeal under section 83(p) could not be entertained unless the appellant had paid the aggregate tax assessed (section 84(3)). In the case of a large institution or substantial corporation the exception where the appellant "would otherwise suffer hardship" (section 84(3)(b)) could not apply. "Hardship" meant financial hardship. Reference was made to Don Pasquale v. Customs and Excise Commissioners [1990] STC 556. It was irrelevant to the issue of statutory construction that the VAT and Duties Tribunal had entertained the present appellant's appeals in circumstances where it had paid tax only on the "preferred assessments". Liability should not turn on the exercise of an administrative discretion. The existence of a power of care and management did not warrant the imposition of a heavier burden than that sanctioned by statute; the existence or otherwise of an important power in the Commissioners should not be left to implication (R. v. Customs and Excise Commissioners, ex. p. Kay & Co. Limited [1996] S.T.C. 1500, per Keene J. at page 1522). Reference was also made to Vestey v. Commissioners of Inland Revenue [1980] AC 1148, per Lord Wilberforce at pages 1171-3. Under Community law (from which VAT stemmed) reliance on administrative discretion or practice was not a valid fulfilment of Treaty obligations (Commission of The European Communities v. Italian Republic, Case 145/82 (1983) E.C.R. 711 at paras. 10-11, a case recently relied on by a London VAT and duties tribunal in City of London Corporation v. Commissioners of Customs and Excise, 5 February 2002, unreported). Accordingly, sections 73(9) and 84 of the 1994 Act should not be construed with an eye to possible mitigation of their effect by administrative action. The effect under the statute of making and notifying the alternative assessments in this case was, if competent, to impose double taxation. In holding that alternative assessments were competent, the tribunal had relied on the recognition of the validity of such assessments under direct tax regimes. But the analogy was misconceived. The arrangements for the imposition and recovery of direct taxes (such as income tax and capital gains tax) were quite different from those in respect of VAT. Reference was made to the Taxes Management Act 1970 section 29(1), section 55(2), (3), (4) and (5) and section 32. In Lord Advocate v. McKenna 1989 S.C. 158 reliance had been placed on section 32. Moreover, where alternative assessments had been found acceptable in relation to direct taxes, that had been in circumstances where different taxes (income tax as against capital gains tax) were claimed in the alternative or at least where the alternatives arose under different Cases in Schedule D of the Taxes Act. These gave rise to different charging provisions, not simply alternative bases for the same charge. Reference was made to Reg. v. Freshwell Commissioners, ex parte Clarke [1971] 47 T.C. 691, Bath and West Counties Property Trust Limited v. Thomas [1977] 1 W.L.R. 1423, Bye v. Coren [1986] S.T.C. 393, Lord Advocate v. McKenna (in the Outer House) 1988 S.L.T. 523 and S.J. Grange Limited v. Customs and Excise Commissioners [1979] 1 W.L.R. 239. The present assessments did not involve different charging provisions, but simply alternative bases. They could (and should) have been contained in a single assessment in respect of the relevant transaction or series of transactions with, if appropriate, alternative legal bases being advanced within it. This had in effect been done in the assessments which were the subject of appeal EDN/01/91. If the appellant's approach to the construction of sections 73(9) and 84 were correct, it followed that the assessments made were not "to the best of [the Commissioners'] judgment" within the meaning of section 73(1) and were accordingly inept. The decision to issue alternative assessments was unreasonable in the "Wednesbury" sense. Reference was made to Rahman v. Commissioners of Customs and Excise [2002] EWCA Civ 1881. The Commissioners had misconstrued their powers. They had proceeded to make alternative assessments when their power was to make a single assessment of the taxpayer's liability. Administrative convenience could not confer a power. If they had conceived that any later difficulty could be resolved by administrative concession, they had again addressed the wrong question. Any collateral consideration unrelated to the calculation of tax could not be a basis for "best judgment". Although, if the appellant was right, the Commissioners would not, by reason of time bar, now be able to proceed by single assessments against the appellant, in every other case they would suffer no disadvantage, as they could advance alternative bases within any single assessment.
12. Mr. Young for the respondents, in an equally lucid and attractive response, submitted that the Commissioners had, under section 73(1), power to make and notify two or more alternative assessments, a power which could be exercised to ensure, where there was some uncertainty of law and/or of facts, that the correct tax was in the end collected. No question of double taxation arose. The appellant had in each case been called upon to make only one payment (on the "preferred" assessment); on appeal the tribunal's disposal would result in the appellant being assessed in only one amount (if any) of tax; the appellant had legal rights which would prevent the enforcement of the aggregate of alternative assessments. The taxpayer suffered no prejudice. The alternative assessments had been based expressly "on the evidence obtained to date"; some material (including intentions for future use and any commercial reasons for the structural arrangements adopted) was peculiarly within the knowledge of the appellant. The assessments made were distinct but truly alternative. They involved in each case two distinct analyses, two different calculations and two different results as to the tax payable. In these circumstances the Commissioners took the view that they required to issue distinct but alternative assessments. The procedure adopted by them in relation to the assessments subject to appeal EDN/01/91 were consistent with this approach; while the "alternative" assessments there under appeal themselves included two legal arguments, both of them were advanced within "abuse of process" and involved the same calculation of, and result in, tax. While the statute did not expressly sanction alternative assessments, there was nothing in it which was inconsistent with so proceeding in appropriate circumstances. It served the need to protect the Revenue where there was uncertainty as to the law or as to the facts or as to both and ensured that the correct tax was in the end collected. Ridgeons Bulk Limited v. Commissioners of Customs and Excise [1994] S.T.C. 427, while distinguishable, illustrated the need for distinct assessments where different foundations for the charge to tax were relied on. The technique of alternative assessments was well-recognised in the field of direct taxation. Reference was made to Lord Advocate v. McKenna (in the Outer House). The statutory framework in respect of VAT involved a degree of flexibility, including in appropriate circumstances and subject to any applicable time bar, the issue of further or supplementary assessments (sections 73(6) and 77(6)). That was understandable in the context of a tax which fell to be collected and accounted for by the taxpayer. What was required was a practicable and workable arrangement which did not prejudice the taxpayer. A practical solution had been adopted, with respect to a "global" assessment, in S.J. Grange Limited v. Commissioners of Customs and Excise, though Lord Denning M.R. had there read certain words into the statute. Here it was possible, without reading in any words, to accept alternative assessments to VAT as a legitimate and practicable procedure which involved no prejudice to the taxpayer. The respondents accepted that, where alternative assessments were made and notified, the effect of section 73(9) was that two debts were created. But, even where an assessment had not been subsequently withdrawn or reduced, the Commissioners had a statutory discretion which in all cases they exercised to the effect of regarding the alternative debts as mutually exclusive. Moreover, the taxpayer was protected both on appeal and in enforcement proceedings; neither the tribunal nor a court would allow enforcement of these debts in the aggregate. As to payment being a precondition of appeal to the tribunal, there was no question of an appellant against alternative assessments requiring to pay the aggregate of the sums assessed. In any event, "hardship" within the meaning of section 84(3)(b) was wider than pure financial hardship and should be construed as including the oppression which would arise by requiring the aggregate amount to be paid or deposited as a precondition of appealing against alternative assessments. The purpose of section 84(3) was simply to protect the Revenue. As to "best judgment", the appellant's first argument on this aspect fell if its earlier propositions were unsound; as to its second argument, there was no warrant for any inference that the Commissioners had adopted alternative assessments for some collateral reason, such as to secure a technical advantage. In Courts plc v. Commissioners of Customs and Excise, 13 November 2002, unreported, a tribunal had recognised the validity of a "protective" assessment. As to the legitimacy of alternative assessments, there was a compelling analogy with the collection of direct taxes; the validity of so proceeding had been repeatedly recognised at the highest levels of authority. Reference was made to Bird v. Inland Revenue Commissioners [1989] 1 A.C. 300, per Lord Keith of Kinkel at page 325, Lord Advocate v. McKenna (in the Outer House) per Lord Coulsfield at pages 526-8, Lord Advocate v. McKenna (in the Inner House) at page 164, Inland Revenue Commissioners v. Wilkinson [1992] S.T.C. 454, per Scott L.J. at page 458. The statutory framework for the collection of direct taxes was not in this respect significantly different from that for the collection of VAT. The fact that under section 55 of the Taxes Management Act 1970, as originally enacted, there was no requirement to pay the assessed tax as a precondition of appealing had not, it seemed, influenced the judicial approach to alternative assessments in direct tax cases. In any event, that section had been amended by section 55 of the Finance (No. 2) Act 1975 which made tax charged by an assessment due and payable unless a successful application to postpone payment was made. The latter arrangement was close to that applicable in respect of VAT. While there was no direct equivalent for VAT to section 32 of the Taxes Management Act 1970, the existence of the latter provision had not, in the authorities, been crucial to the recognition of the validity of alternative assessments.
13. Section 73(1) of the 1994 Act empowers the Commissioners in certain defined circumstances to assess the amount of VAT due from a taxable person to the best of their judgment. That power has been held to include power to make a "global" assessment, that is, a composite assessment in respect of more than one accounting period (S.J. Grange Limited v. Commissioners of Customs and Excise; Don Pasquale v. Customs and Excise Commissioners, per Dillon L.J. at page 562). Section 73(6) empowers the Commissioners, subject to time limits and in circumstances where further relevant evidence comes to their knowledge, to make another (additional) assessment. Section 77(6) empowers the Commissioners in certain defined circumstances to make a supplementary assessment. The concept of alternative assessments is not, any more than that of a "global" assessment, to be found in the statutory language, which accordingly does not expressly sanction such procedure; nor does that language expressly exclude it. The issue in this case is whether it is implicitly within the powers of the Commissioners, in circumstances such as the present, to make under section 73(1) alternative assessments, in the sense of distinct assessments in respect of the same transaction or series of transactions but expressed to be in the alternative. The point is apparently novel in relation to VAT. In the present case the Commissioners, for reasons which have been described, made and notified alternative assessments in respect of various periods during which, it appears, the relevant arrangements in respect of the assets in question were in place. They did so out of a concern that the making of single assessments might, having regard to certain features (including analysis, calculation and result), be open to challenge. It is unnecessary for the disposal of this appeal to decide whether or not that concern was well-founded. The only issue is the competency of the assessment procedure in fact adopted.
14. The burden of Mr. Ghosh's submission was that other provisions of the statute (in particular sections 73(9) and 84(3)) were inconsistent with the existence of a power under section 73(1) to make alternative assessments Section 73(1) involves an assessment of "the amount" (that is, a particular, specified amount) of VAT considered to be due by the taxable person. It is clear that, if distinct, albeit alternative, assessments are made and notified, each of them involves an assessment of a particular, specified amount considered to be due. The effect of section 73(9) is that, subject to the statutory provisions for appeal, each of these amounts, if looked at in isolation, is deemed to be an amount of VAT due from the assessed person. But it does not, in our view, follow that the aggregate of these amounts is so due. Where two assessments in different amounts, made and notified contemporaneously, are so made and notified expressly as being in the alternative, they are, in our view, not independent but interrelated. As such, they are mutually exclusive and not exigible in the aggregate. It is quite clear that no court would knowingly grant decree in such circumstances for the aggregate amount. Nor would it be proper for the Commissioners to institute legal proceedings for the aggregate. The vexatious and oppressive character of so acting was, in the field of direct taxes, made plain by Scott L.J. in I.R.C. v. Wilkinson at page 458, where his Lordship observed that it was a matter of regret that no apology for that oppression had ever been tendered to the taxpayer. The same impropriety would arise in respect of any proceedings instituted by the Commissioners to recover the aggregate of VAT amounts assessed by them in the alternative. Likewise, it would be improper to attempt to use diligence, whether on the dependence of any action or summarily, for the aggregate amount. It is true that a taxpayer so oppressively treated might, in order to obtain relief, require to bring the relevant circumstances to the attention of a court. But that is no different from many other cases in which an unfounded claim is made against a party. In circumstances such as these, the taxpayer is not reliant on the Commissioners exercising in his favour any statutory discretion vested in them under section 73(9) in respect of recovery of tax. The Commissioners simply have no right to recover the aggregate amount.
15. With respect to the right of appeal, similar considerations apply. In the circumstances figured "the amount which the Commissioners have determined to be payable as VAT" within the meaning of section 84(3)(a) is, where both of the alternative assessments have been appealed, not, in our view, the aggregate amount but the higher of the two amounts. It was on this basis that the tribunal, correctly in our view, exercised jurisdiction to entertain the appellant's appeals to it. Don Pasquale v. Customs and Excise Commissioners is distinguishable on this matter. There it was held that there had been a single global assessment; for that reason the whole amount assessed had to be paid or deposited before the appeal could be entertained. We find it unnecessary to express a view as to the scope of "hardship" within the meaning of section 84(3)(b).
16. It is unnecessary in these circumstances to rely on authority concerned with the use of alternative assessments in the context of direct taxes. It is, however, of interest to note that, in a series of cases, the courts have found no difficulty in recognising the validity in appropriate circumstances of alternative assessments without there being any express statutory provision sanctioning such procedure. In Bird v. Inland Revenue Commissioners at page 325 Lord Keith observed that there was no objection to the Revenue pursuing as alternatives two incompatible claims to tax. He cited, with approval, the approach adopted in Bye v. Coren (where Lawton L.J. at pages 394-5 described the like practice in income tax cases as being one which "has long been accepted as being a sensible and proper way of dealing with difficult cases"). The practical justification for the practice was explained in the Outer House by Lord Coulsfield in Lord Advocate v. McKenna at page 527; the competency of making separate assessments on an alternative basis was confirmed in the Inner House. In all these cases the primary ground of judgment did not depend on any specialty in the tax collection regime governing the taxes there in question. In particular, no specialty is, in our view, presented by the availability in relation to direct taxes of section 32 of the Taxes Management Act 1970. That provision (which empowers the Board of Inland Revenue to direct the vacation, in whole or in part, of an assessment) appears to be broadly the equivalent of the final part of section 73(9) of the 1994 Act (under which the Commissioners of Customs and Excise have the power to withdraw or reduce an assessment). We see no good reason why in appropriate circumstances similar considerations should not apply in the framework for collection of VAT, albeit that framework is not identical with that for the collection of direct taxes. Nor do we see any good reason why the use of alternative assessments should be restricted to circumstances where the charging provisions are wholly distinct. As with direct taxes, alternative assessments for VAT provide in appropriate cases a practical and workable machinery for the ultimate recovery of the tax properly due.
17. In the present case, where the preferred assessment and the alternative assessment in each case proceeded on different calculations with different results, the use of distinct but alternative assessments was, in our view, competent. It was within the power of assessment conferred on the Commissioners under section 73(1) and was to the best of their judgment. There is no basis for concluding that it proceeded on any collateral consideration. For these reasons the appeal is refused.