How do I bulk delete 2400 transactions in one go from before I started the business?

Let me help you removed those transactions in QuickBooks, @kcbreaks-hotmail.

If transactions are downloaded from your bank, you can only batch exclude them. This will remove the transactions from your tax year calculations in the Home or Expense screens. To do so, please follow these easy steps:

1. Navigate to the Transactions menu.
2. Check the box beside Date.
3. Select the Exclude icon.
4. Then hit Apply. 

If transactions are manually entered, you can batch delete them. Here's how:

1. Go to the Transactions menu.
2. Check the box beside Date.
3. Click the Delete icon.
4. Tap Apply.

For more info about the process, please see this article: Exclude or delete transactions in QuickBooks Self-Employed. 

You can also visit our Categorise transactions page to help you in managing your QuickBooks Self Employed account. It includes steps on how to record your self-employed income and expenses, and prepare your Schedule C. 

Let me know if you need further assistance in deleting transactions in QuickBooks. I'm always here to help you. Have a good one.