How do I create a contract to attached with an invoice for the client/customer to sign and also pay?

I'm glad to guide you through the steps on how to attach a contract to the invoice, info@tinytransit.

QuickBooks Online lets you attach files to the invoice. And, I'm here to help you accomplish this task.

Please follow the steps I've outlined below.

1. Click +New to create an invoice.
2. Complete all necessary fields.
3. From the bottom left, select Attachments.
4. Browse and select the document you want to attach.
5. Click Open.
6. Mark the Attach to email box.
   
7. Click Save and send.
8. Your client or customer can then see the attached contract through email.

If you need the customer to pay invoices online, you can turn on this method. Here's how;

1. Click Settings ⚙.
2. Select Account and settings, then the Sales tab.
3. From the Online delivery, select Online invoice.
   
4. Click Save, then Done.

When you create an invoice, make sure to select the payment method you want the customer to use. Here's a screenshot for your visual guide.

You can use this process when you have a QuickBooks Payments account. Check out this link if you want to sign up: Take and process payments with QuickBooks Payments. 

Get back to me by commenting below if you have additional questions about attaching a contract to the invoice. I'm always right here to help you.

info@tinytransit 

If you are running a service company, explore this app as another option. When a client accepts your estimate with the engagement letter, it automatically releases an invoice.

https://get.practiceignition.com/quickbooks