inventory register

Browse and you will find lots of images on the internet e.g. https://exceldatapro.com/inventory-control-template

If by inventory account you mean the inventory account in the general ledger, then it doesn’t “relate” – it is a register outside of the double-entry bookkeeping system that is used for control (just as a non-current asset register is “outside” the D/E bookkeeping system).

If you look at the example I have suggested and this was as at the reporting date – column 5 is the quantities that should agree to the physical count and column 4 are the prices that would be agreed to purchase invoices on a sample basis.

If all prices/quantities are correct then the total of column 6 would be the basis of the y/e inventory valuation a single double-entry that is recorded as a period end adjustment:
Dr Inventory (SoFP)
Cr Inventory (SoPL)

If any inventory then needs to be written down to NRV:
Cr Inventory (SoFP)
Dr Inventory (SoPL)

To test for completeness of recorded inventory/cash/non-current asset – the direction of testing is from “physical” (i.e. it exists) to “book”. So if you count 100 units of product ABC in the warehouse, you would hope (1) that product ABC is include in the inventory register (or other record of all inventories) – e.g. column 2 of the example and (2) that the balance (column 5) is also 100.

You’re very welcome!