You have 2,000–5,000 contacts in Viber or Telegram and migration seems like exporting a file. In practice that logic cost one store its number 15 minutes after starting outreach - on message 83. How to validate the list, who you can actually reach on WhatsApp, and how to write a first message that won't read as spam from a stranger.
Agencies hear "move our Viber list to WhatsApp" regularly - usually from clients sure it's file export and chat import. It isn't: WhatsApp can't accept chat history or client metadata from other messengers; it only works with phone numbers. Migration means starting communication from scratch - first find who's on WhatsApp, then write a first message they won't close with "Report." Both parts, in order.
Main task framing error. WhatsApp identifies users by phone number, not Telegram or Viber internal IDs - the only thing you can physically move is a number list. No official Meta tool imports client metadata, chat history, or CRM tags from third-party messengers - see WABA overview.
Chat history, funnel labels, files, and order statuses don't move - restore manually from your CRM, not the source messenger.
Critical: opt-in for Viber or Telegram doesn't legally or technically carry to WhatsApp. To Meta's antispam you're a complete stranger with no interaction history on that number - see cold vs warm contacts.
| Item | Transfers to WhatsApp | Comment |
|---|---|---|
| Phone number | Yes | Only transferable unit |
| Name/segment | Yes, manually | From your CRM, not source messenger |
| Chat history | No | Different closed protocols and DB structure |
| Telegram chat export files | No | HTML/JSON backup for human reading; WhatsApp won't import |
| Opt-in consent | No | Valid only in the channel where given |
Technically: match phone number to internal identifier (JID) on Meta servers. Two working paths, different error costs.
Official path - Cloud API. WABA contact check returns valid or invalid. Legitimate, but nuance: mass one-shot validation of a cold list via WABA token without follow-up messaging is in some practice treated as data-scraping pattern and may trigger temporary business account block. No confirmed official Meta position - practice observation, not documented rule; treat as risk, not guaranteed problem.
Gray path - libraries like Baileys. Software uses methods like onWhatsApp checking socket or avatar. Reverse risk: multithreaded checks from one account without proxy at high speed bans the registrar number almost instantly - see ban mechanics and behavioral anti-spam.
Migration practice observations (especially CIS segment): active WhatsApp account share usually 70–88%. Not universal guarantee - depends on region, contact age, original collection channel. Planning benchmark, not promised result.
No Meta data - figures below from operator practice, not official limits.
Forum observation: if invalid share in one batch exceeds ~25–30%, antifraud may flag session as parser or random-number generator. Unconfirmed - but risk factor when batching checks, especially on old uncleaned lists.
Same list reacts differently by recency. Before first WhatsApp message, split at least three segments - see database segmentation:
Better segmentation = first message read as care, not stranger spam.
Core principle: first message isn't sales - it's context. Answer three questions: who writes, how they got the number, why WhatsApp - see first cold message.
Working structure:
Some experts suggest Utility category in WABA - no prices, links, or sales images - lowers irritation and eases template moderation. Practitioner recommendation, not formal Meta migration requirement.
| Failed scenario | Working scenario | |
|---|---|---|
| List | ~2000 Telegram-bot contacts, no validation | ~5000 Viber contacts, validated, ~12% inactive filtered |
| First message | Promo catalog blast, no context | Service notice reminding contact source + soft question |
| Outcome | Ban ~message 83 in ~15 min - invalid numbers + spam reports | ~42% response rate, ~0.05% spam rate, list into CRM |
Similar scenarios: identical text to unwarmed list without personalization often burns number around 40–70 sends - recipients didn't expect channel switch. 83 in this case fits same logic - don't treat as exact threshold for your number.
Difference isn't "migrate" idea - failed scenario skipped validation and first message didn't explain why you're writing.
Lowest risk: don't write first - let client initiate. Tools:
wa.me link with lead magnet in source channel post (Telegram/Viber);When client clicks and writes first, they give opt-in formally and factually - removes most cold-first-touch risks - see inbound lead collection and WhatsApp Channel as entry point.
Cutting old channel abruptly at migration loses audience. Common multi-account operator practice:
Practical benchmark, not fixed standard - extend for large B2C lists.
No practitioner consensus - know both sides.
Some insist external cloud checkers: they burn their number pools, not your working account. Others argue cheap third-party checkers sell stale logs or leak validated numbers publicly - safer private scripts with hard delays and mobile proxy rotation.
No definitively correct answer - depends what you trust third parties with: working number or client list.
Before blasting the full list, validate a test segment of 200–300 numbers and test first-message text with context reminder. Shows real WhatsApp hit rate for your list and first-touch spam rate - without risking the whole campaign.
Practical rule:
A client having a WhatsApp account is a technical fact. Willingness to chat there is a separate decision you must earn again - not inherit from another messenger.