Where taxable persons use specific goods and services for the purposes of carrying out both transactions that are subject to VAT and those that are exempt from VAT, the input tax must be attributed to both categories of transactions, normally on the basis of the "pro rata". In this article, the author discusses some specific aspects of the pro rata, including the treatment of the disposal of used capital goods, determination of the rate of deduction of input tax where taxable persons are also engaged in non-economic activities, and the effect of self-supplies of goods on the pro rata.