If I do a stockcount and need to write stock in, is there a way to do it without raising a Purchase Invoice?
Even if I could just undo/change a previous Inventory Write-off to correct the balance, I’d rather not compromise historical data.
I tried entering a negative figure into the Inventory Write-offs function, but it had the same effect as zero on the stock’s quantity balance.
You can do a Journal entry to correct a previous inventory write off
Debit - Inventory On Hand - Item - Qty - Value
Credit - Inventory write off,
Write-on is a bit unusual. How did inventory items suddenly appear in your inventory? If it was by mistake of previous write-off. You should fix historical transaction so your books actually reflect the reality.
If you really don’t want to fix historical transactions, then journal entries is the way to go as @Brucanna suggested.