The purpose of this study was to quantify the costs and benefits to employers of operating the PAYE and NI systems. Variables Type of business, including number of employees (full-time and part-time), percentage of employees paid weekly/ monthly/other, turnover, size of PAYE and NI payments, labour turnover and SIC. Costs of time spent by proprietors/directors, computer staff and other staff; fees paid to advisers; costs of special difficulties with PAYE and NI; any other costs. Respondents were asked to estimate what percentage of costs were incurred at the end of the year; what type of documentation was used; whether PAYE work was done entirely within the firm or not. The main benefit to firms was in improved cash flow: variables needed to evaluate this benefit included PAYE and NI payment made; percentage of staff paid monthly/weekly/other; date of payment for monthly paid staff.