QB Issue Resolution:

There is no function in QBO to affect inventory item cost/value.  And you should not be adjusting value in normal operations.

If you had, -143 as the qty, then you sold what you do not have.  You need to enter a purchase for 157 if you have 14 on hand now.

If you are saying that QBO says you have 143 on hand, and have 14 actually on hand, you need to find out how that happened.  Generally it means you are not using the inventory item on an invoice or sales receipt to sell it as is usually done.

You can do an inventory adjustment from the plus menu, and lower the qty on hand, the adjustment account should be the default, COGS-shrinkage

You can also do the adjustment to increase the qty on hand, however it is not free, the cost will be taken OUT of the adjusting account to restock the items.

Resolution for Issue 'Year end inventory: QB on hand -143 cost each $2.00, asset value $ (286.00), actual qty 14 @ $2.00 each ,my new asset value is $28.00, how do I input the new value?' available: Yes (Solved).
Source: Intuit Community forum.

Year end inventory: QB on hand -143 cost each $2.00, asset value $ (286.00), actual qty 14 @ $2.00 each ,my new asset value is $28.00, how do I input the new value?: this issue or error code is a known issue in Quickbooks Online (QBO) and/or Quickbooks. Support for this issue is available either by self-service or paid support options. Experts are available to resolve your Quickbooks issue to ensure minimal downtime and continue running your business. First try to resolve the issue yourself by looking for a resolution described below. If it is a complex issue or you are unable to solve the issue, you may contact us by clicking here or by using other support options.

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