A trader who buys and sells goods will normally have on hand a quantity of goods which he has purchased but not yet sold. These are called his trading stock. A manufacturer who buys raw materials, processes them and sells the finished product will normally have on hand some unused raw materials, some partly manufactured goods and some finished goods awaiting sale. The first and last are stock, the partly processed goods being sometimes called stock and sometimes work in progress.
After giving other illustrations, the learned authors say:
Unless a trader is on a "cash basis" it is clear that at the end of his first trading period some figure must be added to the credit side of his accounts in respect of his stock and work in progress, otherwise his accounts would not fairly show the profit of the period. These items should normally be brought in at the end of the first trading period at their cost and deducted at the same figure in opening the account of the second trading period.
It does not seem to me to matter whether partly manufactured goods are called "work-in-progress" rather than trading stock but on the whole it seems preferable to regard them as trading stock because in truth they represent trading stock, namely raw materials, in the course of transformation into a different kind of trading stock, namely finished products. Something which arises out of work done on trading stock in order to produce other trading stock may be accurately described itself as trading stock. I am not able to agree with the observation of Mahoney J. that the House of Lords in Ostime (Inspector of Taxes) v. Duple Motor Bodies Ltd. [35] regarded work-in-progress as being essentially different from trading stock and to be treated by way of contrast with it. The reasons given by their Lordships demonstrated that the approach to work-in-progress is identical to the approach properly to be made to stock in trade in the sense of that which is purchased, or that which is manufactured. This, I think, is apparent from the speeches of Viscount Simonds [36] , Lord Reid [37] , and Lord Guest [38] . The case itself was concerned only with the proper method of valuing work-in-progress and took for granted the proposition that that which is truly work-in-progress should be brought into account in the ascertainment of the profits and gains in the same manner as raw materials and finished products, i.e. at cost or market value whichever is the lower, in accordance with principles long settled in relation to stock-in-trade in the narrower sense. The problem there was how cost should be ascertained in the case of work-in-progress. The case does not draw any distinction between the valuation of trading stock in the narrower sense of goods purchased on the one hand and work-in-progress on the other, save to observe that in the former case cost may be readily ascertained, whereas in the second, difficulties are encountered. The case is by no means authority for the proposition that work-in-progress is to be taken into account when it arises out of work done on property which is not itself trading stock in the sense of raw materials.
1. [1961] 1 W.L.R. 739; [1961] 2 All E.R. 167; (1961) 39 T.C. 537.
2. [1961] 1 W.L.R., at pp. 748-749; [1961] 2 All E.R., at p. 170; (1961) 39 T.C., at p. 567.
3. [1961] 1 W.L.R., at p. 751; [1961] 2 All E.R., at p. 172; (1961) 39 T.C., at p. 569.
4. [1961] 1 W.L.R., at p. 757; [1961] 2 All E.R., at pp. 176-177; (1961) 39 T.C., at p. 574.