If I have the Bank transfer option on my invoices, do I have to send my bank account details and routing number separately to the client?

Hi, michele-anderson. 

Thanks for visiting the Community space. I'll make sure that your clients can pay invoices online via bank transfer. 

No need to send your bank account details and routing number to your client, the payments go into the external bank account you pick.

Before sending an invoice to your customer, let's check and make sure the right bank account is set up. Let me guide you how:

1. Go to the Gear icon and select Account and Settings.
2. Select the Payments tab, then go to the Deposit accounts section.
3. Select Change to edit your instant deposit info.
4. Click Save, then Done. 

In case you need customers to pay invoices using credit cards, you'll want to set up a payment method on QuickBooks. Then, select the payment options on the invoice. 

I've added this page to learn how to accept customer payments for online invoices: Take and process payments in QuickBooks Online. 

Let me know if you need additional information on how to handle customer transactions in QuickBooks. I'll be right here to help you.