I would like to change the Income Account under the Accounting settings for an item. I want to make sure that this change is only reflected prospectively, going forward, and not for historical transactions. When I hit save, NetSuite alerts me that "You have changed account(s) for this item. Click OK to update the accounts on existing transactions, or Cancel to stay on this page." I'm interpreting this message that it will change all historical transactions. Is there a way to only change this account for transactions going forward, and leaving the historical transactions alone?

Best practices is to inactivate the item and create a new one with the new account.

ok, thank you @Karina - much appreciated 🙏

It only updates transactions in open period. So you can do it right after you close a period. Its not best practice to create a new item, since you lose all transaction history (not lise per say but you have transactions for the same item on two item records)