After an invoice has been generated, how do i switch the income account it posted to? without altering the amount or customer? just the GL account needs to be changed?

Hi vcatax,

Making changes to your invoices is easy in QuickBooks Online. All you need to do is reopen the transaction to edit the details.

Invoices are transactions that simply show the amount owed by the customer. Since money hasn't yet been received, there aren't any accounts to direct funds to on that transaction. If you mean you'd like to change the account on the payment received or a sales receipt, here's how you'd go about that.

Change the account funds are deposited to on a payment received

1. Click Sales in the left-hand menu.
2. On the All Sales tab, find the payment in question.
3. Click the payment to open the transaction.
4. Find the Deposited to field and change it to the appropriate account.
5. Hit Save and close.
6. Read the warning and hit Yes to save it.

Change the account funds are deposited to on a sales receipt

1. Click Sales in the left-hand menu.
2. On the All Sales tab, find the sales receipt in question (Tip: You can use the Filter option to see only sales receipts).
3. Click the sales receipt to open the transaction.
4. Find the Deposited to field and change it to the appropriate account.
5. Hit Save and close.

Most transactions in QuickBooks Online can be changed in this way. Here are a few links with more information about the ones I've mentioned in my response.

How to create an invoice (also covers receiving payments)

Create and send a sales receipt

Should I use an Invoice or a Sales Receipt?

That should get you on your way! Let me know if you have more questions. :)