If you have posted a transaction to the wrong period or for the wrong amount and wish to reverse it, then you need to directly reverse it out in the same period as the original journal, by creating and posting a reversing or opposing journal in Dimensions, as follows:
Ribbon style menu:
Select Financials from the main menu
Select Journal, or VAT Journal depending on the type of the original
Click the Options icon and select the option to Batch Transaction if you wish (optional)
Select the same period the original incorrect posting is in
Tab to the detail page and create lines for the same Nominal Accounts and for the same amounts as the original journal but with opposite credit/debit line types, e.g. a credit line instead of debit line.
Click Save to post the journal or save it to the batch.
Classic/Module Menus style menu:
Select Nominal Ledger from the navigation bar
Select Transactions, Journals, or VAT Journals depending on the type of the original
Follow as from step 3 above.
Once posted to the ledger, this will reverse any monetary values posted to accounts previously. The original journal will still be visible.