What does CLI mean?
CLI (Calling Line Identification) is the caller's number shown to the person receiving the call. A CLI route promises to deliver that number intact to the destination network.
A non-CLI route does not guarantee this — the number may be replaced, hidden or altered along the path.
Why CLI delivery matters
- Higher answer rates — people are more likely to pick up a recognizable number.
- Call-backs work — recipients can return missed calls.
- Compliance — many markets and verification schemes (such as STIR/SHAKEN in North America) expect accurate caller ID.
- Two-factor and verification calls often fail without a valid CLI.
Where non-CLI routes fit
Non-CLI routes cost less and can suit traffic where caller ID is not important. The trade-off is typically lower answer rates and less predictable quality.
How to test route quality
- Place test calls to real handsets and confirm the displayed number.
- Track ASR (answer-seizure ratio) and ACD (average call duration).
- Watch post-dial delay and audio quality.
- Re-test periodically — routes can change over time.
Frequently asked questions
What is the difference between CLI and non-CLI routes?
CLI routes deliver the caller's original number to the recipient; non-CLI routes do not guarantee it and are usually cheaper.
Do CLI routes have better answer rates?
Generally yes, because recipients see a real, recognizable number and are more willing to answer.
Which route type should a call centre use?
Most call centres and verification services choose CLI routes because answer rates, call-backs and compliance depend on accurate caller ID.