I have accidentally pressed paid on a clients invoice instead of sending it to their email Is there a way I can resend the invoice please

You'll first have to delete the payment that's linked to the invoice in QuickBooks Online (QBO), @jojaggard. This way, you're able to resend the invoice to your client's email and manage your transactions accordingly. Let me guide you how.

1. Go to the Sales menu.
2. Select Invoices.
3. Find the invoice, then click it to open its activity.
4. Click the View payment [number] link to view payment details.
5. Choose the More option below, then select Delete.
6. Select Yes to confirm.

After that, find the open invoice. Then, select the drop-down arrow beside the Receive payment option under the Action column to resend the invoice (Please see the screenshot below for your reference). This way, you're able to let your customer pay the invoice accordingly.

Also, QBO gives you the tools to create attractive, professional-looking invoices. This way, you're able to add the info that matters most to your business. If you wish to know more about this, I'd recommend checking out this article: Customise invoices in QuickBooks Online.

Let me know how it goes in the comments below. If you have other concerns about resending invoices or inquiries about managing your sales transactions in QBO, I'm just around to help. Take care always.