When a supplier has sent you their invoices you can record it on EQ against the matching purchase order. By doing this you will be able to return to the costings screen and compare estimated costs with actual costs. You can also run costings reports. The procedure is very similar to recording purchase credit notes.
This article covers:
Allocate specific values to a product
Allocate the invoice value proportionally across all products
1. Open the Customer List and go to the Purchase Orders tab or open Projects > Purchase Orders.
2. Right-click on the P/O Ref and select Purchase Invoice:
2. Enter the supplier's invoice number in the box at the top right:
3. Enter the Nett amount and select the VAT rate and click Calculate. The full total will appear in the Invoice Total and the Unallocated boxes.
Allocate specific values to each product
4. Tick the Allocate tick box next to a product and the estimated column is completed with the same price.
If the invoice amount is for a lower quantity (i.e. not all have been invoiced together) change the Qty column.
If the invoice amount is different enter the new amount in the Act. Price (Each) column.
As you repeat and allocate amounts to different products you will see the Unallocated Total decreasing. You should repeat until all of the invoice value has been allocated.
Allocate the invoice value proportionally across all products
4. If the invoice is for the complete order you can use the Auto Allocate button to evenly distribute the invoice value across all products. This is a quicker way to record an invoice but it does not accurately record costs to a particular product, just the whole order.
5. Tick the Update Actual Costs box if you want to record the actual cost price (this is the actual price that appears in the costings screen and in reports). If you have only recorded an invoice for a quantity of 2 out of 4, you may wish to untick this, so that the costs do not look disproportionate against the total value. When you have recorded all 4 you could then tick the box.
6. Click 
Update to save and close the window.
Multiple Purchase Invoices
If your order is split across multiple invoices you can return and repeat all the above steps for another invoice number. Once a purchase invoice is entered, it will be recorded with its invoice number on the Purchase Invoices tab of the projects screen as well as being visible when you return to the screen to record subsequent purchase invoices here:
Optional
The 2 boxes on the left of the Purchase Invoice window are:
Flag Invoice - Optionally set a coloured/labelled flag to mark the invoice for later attention, and work with the flag filters. Right-click the Supplier Inv/Cred. No, value and select from Flags...
Invoice Notes - Optionally record free type notes for extra detail.