Guides
Bulk WhatsApp number check for Indian customer lists (+91)
Check an Indian list for WhatsApp: turn 0, 91, 091 and Hindi-digit cells into +91, keep 6–9 mobiles, get a free estimate, and follow DPDP Act and TRAI rules.
16 min read
Articles tagged “List hygiene”
21 articles.
Guides
Bulk WhatsApp number check for Nigerian customer lists (+234)
Check a Nigerian list for WhatsApp: turn 080, 081, 070, 090 and 091 numbers into +234, fix 00234 cells, get a free estimate, and follow NCC and NDPA rules.
15 min read
Guides
Bulk WhatsApp number check for Philippine customer lists (+63)
Check a Philippine customer list for WhatsApp and Viber: turn 09XX into +63 9XX, keep the 08 mobile blocks, get a free estimate, follow the Data Privacy Act.
17 min read
Guides
Bulk WhatsApp and Zalo number check for Vietnamese customer lists (+84)
Check a Vietnamese list for WhatsApp and Zalo: convert old 11-digit 01X numbers, turn 09X into +84 9X, get a free estimate and follow the 2026 data law.
17 min read
Guides
Bulk WhatsApp number check for Bangladeshi customer lists (+880)
Check a Bangladeshi customer list for WhatsApp: turn 01X, +88 0 and Bengali-digit cells into +880, dedupe, get a free estimate, and follow the 2026 data law.
13 min read
Guides
Bulk WhatsApp number check for Malaysian customer lists (+60)
Check a Malaysian customer list for WhatsApp: fix 01X, 011 and 60 formats to +60, dedupe, get a free estimate, and follow the PDPA 2010 and its 2024 amendments.
13 min read
Guides
Bulk WhatsApp number check for Mexican customer lists (+52)
Check a Mexican customer list for WhatsApp: drop the old +52 1, set the country, dedupe, plan for the 2026 line registry, and follow the new 2025 LFPDPPP.
14 min read
Guides
Bulk WhatsApp number check for Pakistani customer lists (+92)
Check a Pakistani customer list for WhatsApp: turn 03XX, 92 and 3XX cells into +92, drop dead 03 blocks, get a free estimate, and follow PTA and PECA rules.
14 min read
Guides
Bulk WhatsApp number check for Indonesian customer lists (+62)
Check an Indonesian customer list for WhatsApp: fix 08, 62 and 8 formats to +62, dedupe, get a free estimate, and stay within the PDP Law (UU 27/2022).
13 min read
Guides
How to fix a low Meta Custom Audience match rate on a phone list
Why phone lists match poorly in Meta Custom Audiences: missing country codes, dead and recycled numbers, landlines. The format Meta expects and a cleanup order.
11 min read
Deliverability
Number recycling and phone-list decay: how often to re-check your list
Disconnected phone numbers are reassigned to new people, so every list decays. How recycling works, what the US rules say, and a re-check cadence recipe.
7 min read
Guides
Yahoo email checker: how to check if a Yahoo Mail address exists, one at a time or in bulk
To check if a Yahoo email exists, send a test message and read the bounce, or run an account check in bulk. SMTP probes fail at Yahoo; here is why.
15 min read
Deliverability
How much does an HLR lookup cost? HLR lookup pricing explained (2026)
HLR lookup prices per number and per 1,000: what drives the cost, the pricing models on the market, hidden fees, and how to estimate a list before you pay.
7 min read
Guides
How to check if a Gmail, Yahoo or Outlook account exists without sending an e-mail
Check if a Gmail, Yahoo or Outlook account exists without sending mail: why SMTP probes fail at big providers, address aliases, bulk lists and privacy.
9 min read
Guides
Bulk Telegram number check for Asian customer lists (Indonesia, India, Philippines, Vietnam, Hong Kong)
Check Telegram numbers in bulk for Indonesia, India, the Philippines, Vietnam, Hong Kong and more: normalising Asian formats, privacy and unknowns, cost caps.
7 min read
Guides
Bulk WhatsApp number check: how to verify a customer list (CSV upload or API)
Check WhatsApp numbers in bulk: prepare a CSV, get a free estimate, cap the cost, run the job in the dashboard or API, and act on each answer.
8 min read
Guides
How to check if a phone number has an Apple ID (single and bulk)
How to check if a phone number has an Apple ID (Apple Account), one or in bulk: what yes, no and unknown mean, how it differs from iMessage, API examples.
7 min read
Guides
HLR lookup results explained: absent subscriber, unknown subscriber and what to do next
Absent subscriber: the number exists but the phone is off or out of reach. Unknown subscriber: the number is not assigned. Each HLR result and what to do next.
10 min read
Developers
How long is a phone check result valid? Caching HLR, MNP and messaging-app answers
Each phone signal goes stale at its own speed. How often to re-verify numbers, how to cache HLR, MNP and messaging-app answers, and how long to keep them.
8 min read
Deliverability
When does an HLR lookup pay for itself? Break-even math for SMS and OTP costs
A simple cost model for pre-send checks: when an HLR, MNP or carrier lookup costs less than the SMS it saves, with formulas and a worked table.
9 min read
Guides
The Reassigned Numbers Database (RND), explained
What the FCC Reassigned Numbers Database does, how its yes/no/no-data answers and TCPA safe harbor work, what it costs, and where other checks fit.
8 min read
