If there is a multiplier, also known as a k-factor, on your invoice, it would mean that you are considered a high usage tenancy and the actual consumption is too large to be registered by your meter. Multipliers also help to prevent the meter rolling over frequently.
Typically, multipliers of 40, 80 or 120 are a common set up for commercial tenancies which are likely to use a lot of power.
For example, if your multiplier is 40 the meter reads between the start read date and end read date are recorded as one 40th of the actual usage, which is programmed into the meter. Therefore, we need to multiple this by 40 to get to get the actual consumption.