Each roll nominally covered the events of a year ending at Michaelmas (29 September), rather than the calendar year or the regnal year, which was used in the rolls produced by other government departments. The rolls were identified by the regnal year in which they ended. For example, the pipe roll 43 Henry III covers the year to 29 September 1259; Henry III's regnal years began on 28 October, so that the roll actually covers the last month of his 42nd year and eleven months of the 43rd. The annual routine of producing the pipe roll thus began, at least in principle, on the first day of the new Exchequer year, the morrow of Michaelmas: on this day, 30 September, the sheriffs were supposed to appear at the Exchequer, bringing the revenues they had collected, and the process of auditing their accounts began.
We are fortunate to possess a contemporary account of Exchequer procedure, written about 1180, known as the Dialogue of the Exchequer. This presents a picture of the procedure for compiling the rolls which has influenced most historical writing on the topic. As the Dialogue presents it, the Exchequer summoned the sheriffs of the counties to attend twice a year: after Easter, for the view, a sort of interim report where sheriffs paid in the revenues of the first half of the year; and after Michaelmas, for a full audit of the preceding year's revenue and expenditure. At this audit, the sheriff would be confronted by the senior officials of the Exchequer, across a table covered with the chequered cloth which gave its name to the institution. An Exchequer official would use this cloth as a counting device, placing counters in columns to show how much the sheriff owed and how much had been paid. As this took place, a clerk would write up the results of the process in the pipe roll (and two more copies were produced simultaneously).
This picture was misleading for the time when it was written, and became increasingly remote from reality in the thirteenth century. It is clear that, even in the twelfth century, much of the pipe rolls was written in advance of the audit, leaving blank spaces to be filled in with the amounts of cash delivered. As time passed, the sheriffs' contribution to royal revenues, and thus to the content of the rolls, became relatively less significant. Many boroughs and individuals paid their debts directly to the Treasury, rather than having their debts collected by the sheriff. The view became less important. The audit process for the sheriffs' accounts took longer and longer, with the larger counties such as Essex and Hertfordshire requiring up to twelve days. (Several sheriffs were responsible for two adjacent counties. Sometimes these counties accounted separately, as with Shropshire and Staffordshire; sometimes they were treated as a single unit, as with Essex and Hertfordshire.) This meant that the audit of county accounts for the year to Michaelmas might not be finished until the summer of the following year; furthermore, accounts often included payments made after the end of the year with which they were nominally concerned, right up to the date of the audit. The difficulties of bringing a busy sheriff to London for a lengthy audit sometimes meant that a year's accounting had to be skipped, so that county accounts often cover two or three years.
The bulk of the account for each county was simply a repetition of a group of regular payments which hardly varied from one year to the next, and of the entries for unpaid debts outstanding from the previous year. This material could thus be copied out in advance of the audit, leaving spaces to be filled in to accommodate any payments received. New debts could be added at the end of each county's section of the roll. At the audit, after scrutiny of the evidence produced, the details of the net amount owed by the sheriff, and the payments made towards that debt, could be added to complete the record for the year.
The production of county accounts was thus less straightforward than the verbatim record of the audit which was described in the Dialogue. In addition, the pipe rolls came to include much material in addition to the county accounts, known as the foreign accounts, as will be explained in the next section.