I totally understand your frustration. Zoho CRM doesn't have a native way to auto-validate phone numbers or addresses, which leaves sales reps wasting time on bad data.

I actually ran into this exact problem and ended up building a free extension called Data Guardian to solve it.

It adds a "Health Check" button inside your Leads and Contacts. It validates Emails, Phones, and Physical Addresses, and gives you an instant 0-100% Health Score. If the data is bad, it automatically creates a Task for your team to fix it.

It has a 10-day free trial, so you can test it with your own real data without risking anything.

Let me know if you try it out—I'm the developer, and I personally respond to all support questions!