Do customers need a Zoho Account to access the client portal?
It is not necessary for your customers to have a Zoho account. Once you send an invitation to your customers to access the portal, upon accepting the invitation they can login to the portal by using the email address with which they were invited.
Can we delete the comments added in the client portal?
No, you cannot delete comments added in the client portal.
How do we check if our client has viewed the estimate/invoice have sent him?
You would receive a notification in the bell icon on the top right corner stating that your customer has viewed the invoice/estimate.
Also you can simply click on the particular estimate or invoice and check if it has been viewed by the client. A tiny eye icon on the right corner suggests that the client has seen it.
Alternatively, go to the estimate or invoice tab on the home page of Zoho Invoice. Click on the drop down next to All estimates or All Invoices and select Client viewed.
You can now see only the client viewed estimates/invoices.
Will be able to change customer’s email address? Will he now able to view the old invoices in the client portal?
Yes, you can change the email address of a customer. Send him a portal invitation again using the new mail ID, using which he can create a password and log back into the portal. Once this is done, he can view all old invoices you’ve sent him