When i send out emails the address is incorrect for customers to reply

Hi, @mgm-fire-electri. I'm glad to help you set up Construction Industry Scheme or CIS deduction on invoices. 

When you start using Construction Industry Scheme (CIS) in QBO, the system will calculate your deductions, track your withheld or suffered amounts, and create the necessary reports for HMRC. With this, once the customer is set up as a CIS contractor, QuickBooks will automatically show the deduction on their invoices.

To have this enabled, follow the steps below:

1. Log into your QBO account and click the Gear icon.
2. Select Account and Settings.
3. Click to expand the Advanced section.
4. Go to the Construction Industry Scheme (CIS), and mark the Enable CIS box.
5. Enter all the information.
6.  Hit Save and Done. 

Once this feature is on, you can no longer turn it off. However, if you don't want to use it, just disregard this option. You don't need to worry about turning on the feature since it doesn't affect your transaction unless you use it. 

To add this to your customer invoices, ensure to select CIS. I'll guide you on how: 

1. From the Sales menu, proceed to the Customers tab.
2. Click the customer's name and tick the box Is CIS contractor.
3. Enter their UTR number in the Tax info tab.
4. Hit Save.

Here's an article for more information: CIS guide in QuickBooks Online.

Moreover, to ensure you entered the correct email address you use to send invoices to your customers, go to the Invoices tab from the Sales menu. Then, from the Action dropdown, select Send. Check the email you use or add a Gmail address if you haven't done it yet.

You may visit this article to learn how to personalise and add specific info to your sales forms: Customise invoices, estimates, and sales receipts in QuickBooks Online. 

I'll be here if you have any other concerns or follow-up questions about invoices. Stay safe and have a good one!