Identifiers & routing
What is Dynamic number insertion (DNI)?
Swapping the phone number displayed on a website per visitor or traffic source so inbound calls can be attributed to the marketing that drove them.
Definition
Dynamic number insertion (DNI) is the mechanism behind call tracking: a script swaps the phone number shown on the page based on the visitor’s source, campaign, keyword, or session, drawing from a pool of tracking numbers.
Because each number (or number-plus-session) maps to a source, the tool knows that a call to a given number came from, say, a specific Google Ads keyword — without the caller doing anything differently.
Why it matters for agencies
DNI is what makes call attribution granular enough to be useful — not just "calls came from the website" but "this call came from this campaign." That granularity is what feeds back into bidding and reporting.
It’s also a tracking script on the client’s site like any other, which means it can conflict with caching, break on a redesign, or be misconfigured — so it belongs in the agency’s documented tracking setup, not in a silo.
Dynamic number insertion in Phloz
In Phloz, DNI is recorded on the client’s call-tracking node (on or off, with the number-pool size) alongside a health state and last-verified date, and the audit flags the node once 30 days pass without a check — so re-verifying the number-insertion script is a routine rather than something discovered when calls stop attributing.
Frequently asked questions
- How many tracking numbers does DNI need?
- It depends on concurrent visitors per source — session-level attribution needs a large enough pool that two simultaneous visitors from the same source don’t see the same number. Tools size the pool from traffic volume.
- Does DNI hurt SEO with inconsistent NAP?
- It can if misconfigured — search engines and directories expect a consistent business phone number (NAP). Good call-tracking setups keep the canonical number consistent for SEO/GBP and only swap for paid/identifiable sources, or use it carefully.
Related terms
Other tracking-infrastructure concepts agencies run into alongside this one.
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