How to Prepare Your Data for Bulk WhatsApp Number Verification

A practical workflow guide for preparing a bulk phone number check CSV TXT file, formatting identifiers in E.164, and retrieving synchronous account-presence signals.

To perform a bulk phone number check CSV TXT file workflow, you must format all submitted identifiers strictly in the E.164 international numbering standard. Once your list is cleaned of non-numeric characters and local prefixes, you can submit these numbers to the WA Lookup platform to retrieve account-presence signals. Depending on your workflow requirements, you will select one of three service types: ws for basic registration status, ws_avatar to include avatar availability, or ws_business to identify WhatsApp Business accounts. The platform processes these requests through a synchronous check, meaning the verification result for each submitted number is returned immediately in the same HTTP response. This immediate feedback supports efficient list processing and helps teams review account presence without waiting for asynchronous batch completion.

Understanding WhatsApp Verification Signals

When preparing a bulk phone number check CSV TXT file, the first step is determining which account-presence signal supports your specific workflow. WA Lookup provides three distinct service types, all accessed through a single synchronous endpoint. The service_type parameter controls which fields are returned in the response.

Basic Registration Check (ws)

The ws service type confirms whether a submitted phone number is currently registered on WhatsApp. This check returns a registered field, providing a straightforward account-presence signal. It informs internal decisions regarding which numbers in your CSV or TXT file are associated with an platform account-presence signals at the time of the check.

Avatar Enrichment Check (ws_avatar)

The ws_avatar service type includes the basic registration check and adds profile enrichment capabilities. In addition to the registered status, this check returns an avatar boolean value indicating avatar availability. If the upstream service supplies one, it also returns an avatar_url string. This additional context can be one input alongside other checks when reviewing user profiles.

Business Account Check (ws_business)

The ws_business service type checks WhatsApp registration and identifies whether the account uses WhatsApp Business. It returns a business boolean value. This signal helps teams segment their lists by distinguishing standard accounts from business profiles, supporting more tailored workflow routing.

Preparing Your Data File

The most critical requirement for processing a bulk phone number check CSV TXT file is proper data formatting. WA Lookup requires all numbers to be submitted in the E.164 format. E.164 is an international telephone numbering plan that assigns each device a globally unique identifier. To prepare your CSV or TXT file:

1. Include the Country Code: Every number must begin with the appropriate international country code.
2. Remove Formatting Characters: Strip out spaces, dashes, parentheses, and any other non-numeric characters from your list.
3. Omit Leading Zeros: Remove any local trunk prefixes (often a leading zero) that are not part of the international dialing code. For example, a US-based number should be formatted as a continuous string of digits starting with the country code (e.g., 1). Confirming your entire batch adheres to the E.164 standard helps avoid formatting errors during the synchronous check process. A clean, standardized input file is essential for retrieving accurate account-presence signals for every submitted number.

Submitting Your Batch for Verification

Once your bulk phone number check CSV TXT file is formatted correctly, you can submit the identifiers to the WA Lookup platform. The platform utilizes a synchronous check process, meaning results are returned in the same HTTP response as the request, rather than being delivered asynchronously at a later time. For technical teams integrating the service, the documented request contract uses the POST /api/v1/check endpoint. Requests require an X-API-Key header and a Content-Type: application/json header. The JSON body must contain the service_type (either ws, ws_avatar, or ws_business) and the identifier (the E.164 formatted number). Because the endpoint is synchronous, your application can iterate through the CSV or TXT file, submitting each number and receiving immediate feedback. The WA Lookup dashboard supports this workflow by providing comprehensive API key management and reporting tools. Users can monitor their balance, view check history, and access product-level reporting. The dashboard also displays recent checks, balance spend, and 7-day trends, giving teams clear visibility into their verification activity. Furthermore, the platform operates on a pay-per-check model where failed or undetermined checks are refunded automatically, meaning resources are only utilized for successful queries. New accounts can also utilize a $0.10 trial balance to test the registration, avatar, and Business account checks before processing larger lists.

Interpreting Your Results

Understanding the output of your bulk phone number check CSV TXT file is crucial for integrating the data into your broader systems. Every successful check response carries specific fields: id, identifier, registered, transaction_id, status, service_type, and charged_amount_micros. The registered result reports the WhatsApp status fields available at the exact time of the check. It is important to understand the boundaries of this account-presence signal. Additionally, the verification process does not check online status, last seen timestamps, message history, or contact consent. It also does not indicate whether the number can be successfully contacted or if messages will be delivered. The signal simply informs your internal database about platform registration, which can be one input alongside other checks when organizing your CRM or routing records.

FAQ

What is the required format for phone numbers?

All phone numbers must be submitted strictly in the E.164 format. This international numbering plan requires the country code and the removal of all non-numeric characters, spaces, and local leading zeros.

Can I check for WhatsApp Business status in bulk?

Yes, by selecting the ws_business service type, you can check both the basic registration status and whether the account uses WhatsApp Business. This returns a specific boolean value indicating business account presence.

Are the verification results delivered asynchronously?

No, the platform uses a synchronous check process. The verification result for each submitted number is returned immediately in the same HTTP response as the request, rather than being processed and delivered asynchronously.

What happens if a check fails?

The platform operates on a pay-per-check billing model where any failed or undetermined checks are refunded automatically to your account balance.