DomailfixHow to validate phone numbers before you call or message
Wrong phone numbers waste time for sales and support teams. Calls fail, WhatsApp and SMS messages are never delivered, and your CRM fills up with junk. Checking numbers before you use them takes seconds.
What makes a phone number valid?
A valid number has:
- the right country code, such as +91 for India or +1 for the US and Canada
- the right length for that country. Indian mobile numbers have 10 digits after +91
- a number range that is in use. Indian mobile numbers start with 6, 7, 8 or 9, for example
A number can look fine and still be invalid. 5123456789 has 10 digits, but no Indian mobile number starts with 5.
Mobile, landline or toll-free?
Knowing the type tells you how to reach someone:
- Mobile: calls, SMS and WhatsApp
- Landline: calls only, usually an office
- Toll-free (1800 in India): free for the caller, usually a company helpline
- Premium rate: costs the caller extra. Avoid these in a contact list
Write numbers in one format: E.164
The same number can be written many ways: 098200 12345, 9820012345, +91-98200-12345, 0091 98200 12345. Your CRM, dialer and WhatsApp tools work best when every number is in E.164 format: a plus sign, the country code and the number, with no spaces, for example +919820012345.
Cleaning to E.164 also shows you duplicates that were written differently.
Watch for made-up numbers
People often type fake numbers into forms: 9999999999, 9876543210, 1234567890. They can pass a simple length check, so a good validator marks them Risky.
What a validator cannot tell you
A format check cannot tell you whether a phone is switched on today, or who owns it. In India, people can also keep their number when they move to another network, so the network shown is the one the number was first given to.
How to clean a phone list in minutes
- Export your contacts as a CSV, or copy the phone column.
- Open the free phone number validator and choose the country for numbers without +.
- Paste the numbers or upload the file, and click Check numbers.
- Download the CSV. Keep Valid numbers, check Risky ones, and remove Invalid numbers and duplicates.
- Import the clean list back into your CRM, using the E.164 column.
When you call or message numbers in India, follow TRAI's Do Not Disturb (DND) rules, and only contact people who expect to hear from you.
Each number uses 5 credits, and your credits never expire. Check phone numbers now.
Questions and answers
How many digits does an Indian mobile number have?
Ten digits after the country code +91, starting with 6, 7, 8 or 9.
What is the E.164 phone number format?
A plus sign, the country code and the number with no spaces or dashes, for example +919820012345. Most CRMs, dialers and messaging tools expect it.