How do I reallocate activity in one GL Account to another GL account all at once?

Utilize a migration tool. Export your transactions out to XLS, modify it, and import them back in bulk.

https://transactionpro.grsm.io/qbo

Hi there usershauna-blackburn,

Making sure that your transactions are entered in the correct account is important to make sure that your books are balanced. QuickBooks Online allows you to personalize your chart of accounts to organize your books in the best way to benefit your business. I can provide some insight into moving transactions from one account to another.

If you were to want to move all transactions that affect an account into another, you could merge those accounts to have both of them become a single account. You can do so by changing the information such as the name of the account, account type, and more of the unwanted account to match the information in the wanted account. Once the information is exactly the same there will be a prompt asking you if you want to merge the accounts, and you can click yes to have them combined. here's an article with more information on merging accounts, suppliers and customers in QuickBooks Online.

If you were to want to move some transactions from one account to another, but not all the transactions in a single account, you can move them by editing them one by one or possibly find an app that can help you with moving transactions in another account as mentioned by Fiat Lux - ASIA. You can find a selection of applications that can connect with QuickBooks Online by navigating to the Apps section.

If you have any other questions, feel free to reach out here.