The buyer's checklist

12 questions to ask any validation vendor.

Including us. Every vendor in this category — us included — sells certainty; these questions surface what the certainty is made of. The whole list is on this page, ungated: take it to your vendor call. Our own answers are underneath each one, with the receipt linked, so you can hold us to the same standard we're recommending.

01

What exactly did you check before calling this number “valid”?

A good answerA list of the specific checks run — format, carrier records, ported status, live network query — not the word “proprietary.”
OursEvery response carries checks.performed, machine-readable. See a real response →
02

Will your API tell me what it didn't check?

A good answerYes, in the response itself — so your audit trail knows what a verdict was based on.
Ourschecks.not_performed, every response, contractually part of the API. The honesty contract →
03

When was your accuracy last measured — by whom, on what dataset?

A good answerA dated, named measurement with a public dataset and method. “99% accurate” with no footnote is marketing, not measurement.
OursMeasured in public: benchmark № 001, methodology frozen and checksummed before results, us scored alongside everyone from the first re-run. The series →
04

Is the methodology public, and was it fixed before the results existed?

A good answerA pre-registered method — scoring rules that can't move after the numbers arrive.
OursPublished in full, sha-256 posted at freeze. Read it →
05

When you can't perform a check, do you abstain or guess?

A good answerAbstain, visibly. A confident verdict on a check that never ran is the category's worst habit.
OursWe abstain and say so — our own metadata tier reports fixed_line_or_mobile as exactly that, and our benchmark scores abstention as abstention, not accuracy. §5, abstain ≠ wrong →
06

How stale can your carrier and ported-status data be?

A good answerA statement of data source and refresh cadence — numbers port daily; records that don't follow are misinformation with a timestamp.
OursMetadata tier: disclosed as metadata, per response. Licensed carrier/ported data lands at launch and appears in checks.performed only when real.
07

Do unused credits expire?

A good answerNo — and written where it's enforceable, not in a pricing-page footnote.
OursNever. Terms clause, and the ledger shows it. § Credits →
08

Can I cancel without talking to anyone?

A good answerA button. Retention calls are a pricing strategy, not a service.
OursSelf-serve portal, one button. In the Terms →
09

What happens when I hit your rate limit?

A good answerA documented limit, standard RateLimit headers so your code can pace itself, and an honest 429 — nothing silently queued or dropped.
OursPrinted per tier, IETF RateLimit headers on every verify, 429 with Retry-After. Rate limits →
10

Is there a public status page, and does it show raw numbers?

A good answerReal probe counts, not a green dot with retroactive smoothing.
Ours1-minute probes, raw up/total counts, no retro-editing. Live →
11

What do you charge for a lookup that errors?

A good answerNothing. Charging for your own 5xx is self-dealing.
OursInput errors: never charged. Bulk rows that fail: auto-refunded, row by row, visible in the ledger. Errors →
12

Can I export my data and delete my account without a ticket?

A good answerSelf-serve JSON export and immediate deletion — your usage history is yours.
OursBoth, from the dashboard, instant. Your data →

Benchmark № 001 answers question 3 for every vendor

Pre-launch — benchmark results and early API access. One email. We validate emails for a living — we're not going to spam yours.