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What's the importance of selecting the correct invoice date/time?
What's the importance of selecting the correct invoice date/time?

Setting the correct date/time for your invoices ensures that your consumption data is accurate

Nick Neale avatar
Written by Nick Neale
Updated over a week ago

Article Contents


If an invoice isn't added with the correct date and time, your consumption data may be inaccurate. To have a complete understanding of its impact, you need to know two things:

  1. Your consumption between two inventory counts is calculated as follows:

    Consumption = Starting Inventory + Invoices - Ending Inventory

  2. WISK uses the start time of inventory counts for all calculations

Editing an Invoice Date / Time

If you have added an invoice with the wrong date/time, you can edit it on either the WISK Web Portal or mobile app. Learn more here:

Impact of an Incorrect Date / Time

Wrong Invoice Date

If an invoice is added on the wrong date, it may not fall into the correct inventory period. It's very important that the invoice be sandwiched between the right dates so that the Consumption calculation above contains the correct values.

Wrong Invoice Time

The same issue can arise when adding an invoice on the same date as an inventory session.

Since WISK uses the inventory's Start Time to determine when it occurred, it will make a difference whether the invoice time is before or after the inventory has started.

For these instances, we recommend leaving your received stock to the side, doing your inventory (while excluding these new items), then adding the invoice after the inventory has been completed.


Let's say for a given week, you start off with 10 units of an item, receive 6 units from an invoice, then count 9 units the next time you take inventory. Based on the Consumption calculation, you should have consumed 7 units.

10 (beginning) + 6 (received) - 9 (ending) = 7 units consumed

If your invoice with the 6 units was entered at the incorrect time (at a date/time outside of the inventory period), the consumption calculation for the period will look like this:

10 (beginning) + 0 (received) - 9 (ending) = 1 unit consumed

The resulting consumption will be too low for the period that was supposed to contain this invoice and it will be too high for the period that now mistakingly contains this invoice.

Stock Error / Negative Consumption

Whenever you see a Stock Error, also known as Negative Consumption in your reports, it is either due to miscounts or misdated invoices.

If you take the same example as above, but start off with 7 units, look what happens to your consumption when an invoice isn't added correctly:

7 (beginning) + 6 (received) - 9 (ending) = 4 units consumed

7 (beginning) + 0 (received) - 9 (ending) = -2 units consumed

It shows that you gained 2 units with no reason to account for the increase.

You can learn more about stock errors/negative consumption here:

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