Line Types Detected
| Line Type | SMS Capable | Fraud Risk | Notes |
|---|---|---|---|
| Wireless | Yes | Lower | Mobile phones, best for SMS |
| Landline | Limited | Lower | Voice calls preferred |
| VoIP | Varies | Higher | Internet-based, variable SMS |
| Toll-free | If enabled | Low | Business numbers |
Try Line Type Checker
API example:
curl -X POST https://api-service.verirouteintel.io/api/v1/lrn \
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{"phone_number": "15551234567"}'
# Response:
{
"data": {
"phone_number": "15551234567",
"lrn": "5551230000",
"carrier": "Verizon Wireless"
},
"success": true
}Why Line Type Matters
SMS Delivery
Don't send SMS to numbers that can't receive them:
- Wireless — Send SMS freely
- Landline — SMS converted to voice (poor experience)
- VoIP — Check if SMS-enabled before sending
Fraud Prevention
VoIP numbers are commonly used in fraud because they're:
- Easy to obtain without ID
- Disposable (abandon after use)
- Not tied to physical location
Contact Strategy
Match your outreach to the phone type:
- Wireless — Text, then call during day
- Landline — Call during evenings
- VoIP — May be business, call during work hours
Bulk Line Type Checking
Check line type for entire contact lists:
- Upload CSV with phone numbers
- Get line_type for each number
- Segment lists by type
- Filter landlines from SMS campaigns
Need API Access?
- NPAC-verified line type — wireless, landline, VoIP, or toll-free — for any US number
- Included free in every LRN lookup at $0.0005 per query
- Bulk validation available to segment your entire contact list by line type
Line Type Checker — FAQ
How is line type determined for a phone number?
Line type is determined by querying the NPAC database for the number's current carrier classification. The carrier type field distinguishes wireless (mobile), landline, VoIP, and toll-free numbers based on the network the number is registered to. This is more accurate than inference from the NPA-NXX prefix, which doesn't account for number porting.
Does a VoIP line type affect SMS deliverability?
VoIP numbers have variable SMS capability — some VoIP providers (like Google Voice) support SMS, while others don't. VoIP numbers also have higher fraud risk since they're easier to obtain without identity verification. For SMS campaigns, identify VoIP numbers and test deliverability before including them in A2P messaging flows.
What API call returns the line type for a phone number?
Line type is returned in every VRI LRN lookup response in the enhanced_lrn_data.carrier_type field. A single GET /api/v1/lrn?phone_number=+1XXXXXXXXXX&include_enhanced_lrn=true call returns carrier type, carrier name, ported status, activation date, and routing data — all for $0.0005.
Check Line Types
Identify wireless vs. landline vs. VoIP for any number.