How do I send self billing invoice to tax return?

Welcome to the Community, @AnneE. I'm here to ensure you'll be able to send self-billing invoices in QuickBooks Online (QBO).

To assist you in sending a self-billing invoice for your tax return, I highly recommend reaching out to HMRC. They can provide you with detailed steps for the action you need to take. With this, we can also make sure that you can send it successfully. For more information, please visit this link: Self-billing (VAT Notice 700/62). 

Additionally, here's a helpful resource that you can access for future assistance in handling taxes in QBO: Manage taxes in QuickBooks.

Please let me know how this goes. I'd appreciate any updates you can add. If you have follow-up questions about managing your self-billing invoice, feel free to leave a reply below. I'm always around to back you up. Have a great week ahead. Take care.