Sending the same message to everyone is lazy marketing. Segmented campaigns convert 3-5x better than generic blasts because they reach the right people with relevant offers. This guide shows you how to organize WhatsApp contacts into custom groups for targeted message segmentation — the foundation of high-converting WhatsApp automation.

What You'll Need

Before starting, make sure you have:

A connected WhatsApp session — Your account must be connected and showing "WORKING" status. See our connection guide if needed.
Growth or Business plan — Custom groups (available on all paid plans) are a premium feature. The Free plan doesn't include group management. Upgrade here if needed.
A list of contacts — Phone numbers of people you want to message. These can be existing customers, leads, or anyone who's opted in to receive messages from you.

Important: MoltFlow custom groups are different from WhatsApp groups. Let's clarify the difference before we start.

Custom Groups vs WhatsApp Groups

Many people confuse MoltFlow custom groups with WhatsApp groups, but they're completely different features:

WhatsApp Groups:

Chat rooms where all members can see each other's messages
Visible to all participants
Members can see the full member list
Used for community discussions, family chats, team coordination
Created inside WhatsApp app on your phone

MoltFlow Custom Groups:

Your private contact lists — recipients don't know they're in a group
Completely invisible to recipients
Used for organizing contacts for bulk send campaigns
Created and managed in your MoltFlow dashboard
Recipients receive individual messages, not group messages
Persistent and API-accessible — unlike one-time broadcast lists that disappear, MoltFlow custom groups (available on all paid plans) are permanent and programmable

Think of MoltFlow custom groups like email mailing lists — you're organizing contacts for targeted outreach, not creating public chat rooms.

This guide covers MoltFlow custom groups only. If you need help with WhatsApp groups, see our monitoring guides.

Step 1: Navigate to Custom Groups

You'll see the Custom Groups page, which shows all your existing contact groups. Each row displays:

Group name — The descriptive label you gave this group
Member count — How many contacts are in this group
Last used — When you last sent a bulk campaign to this group
Actions — Buttons to view, edit, or delete the group

If this is your first time here, the page will be empty — that's normal. Let's create your first group.

Step 2: Create a New Contact Group

Click the "Create Group" button in the top-right corner of the Custom Groups page.

A modal dialog will appear asking for group details:

Group name (required) — Enter a descriptive name that clearly identifies this audience segment. Good examples:
- "VIP Customers" — Your highest-value buyers
- "Newsletter Subscribers" — People who signed up for updates
- "Lead Follow-ups" — Prospects you're nurturing
- "Event Attendees March 2026" — People who registered for a specific event
- "English Speakers" — Segmented by language preference
Description (optional) — Add notes to remind yourself what this group is for, where these contacts came from, or any special handling instructions. This is for your eyes only — recipients never see it.

Click Create to save your new group.

MoltFlow creates the group immediately and takes you to the group detail page, where you can start adding members.

Using the API, you can create groups programmatically:

bash

curl -X POST https://apiv2.waiflow.app/api/v2/custom-groups \
  -H "Authorization: Bearer YOUR_API_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "name": "VIP Customers",
    "description": "High-value contacts from 2025-2026"
  }'

The API returns the new group's ID, which you'll use to add members in the next step.

Step 3: Add Contacts

Now that you have a group, it's time to populate it with contacts. MoltFlow offers two methods: manual entry and CSV import.

Method 1: Manual Entry

Manual entry works well when you have a small number of contacts (under 20) or need to add people one by one as they opt in.

On the group detail page, click "Add Members".

A text input field appears. Enter phone numbers one at a time, pressing Enter after each number.

Phone number format: Country code + number with no plus sign, spaces, or special characters.

Examples:

US number: 14155551234 (not +1 (415) 555-1234)
UK number: 447911123456 (not +44 7911 123456)
Brazil number: 5511987654321 (not +55 11 98765-4321)

MoltFlow validates each number as you enter it. Invalid formats are rejected with an error message.

Click Save when you're done adding numbers.

Method 2: CSV Import

CSV import is the fastest way to add many contacts at once. Perfect for importing from your CRM, email list, or sales database.

Prepare a CSV file with a phone column header and one phone number per row:

csv

phone
14155551234
447911123456
5511987654321

You can include additional columns (like name, email, notes) but MoltFlow only reads the phone column for group membership. The other columns are ignored — MoltFlow doesn't store contact metadata in custom groups, only phone numbers.

On the group detail page, click "Import CSV" and select your file.

MoltFlow will:

Read all phone numbers from the phone column
Validate each number's format
Remove duplicates (if a number is already in the group, it's skipped)
Add all valid, unique numbers to the group

After import completes, you'll see a summary:

Added: 150 new contacts
Skipped (duplicates): 5 contacts
Skipped (invalid): 2 contacts

Invalid numbers are listed so you can fix them and re-import if needed.

Using the API to add members in bulk:

bash

curl -X POST https://apiv2.waiflow.app/api/v2/custom-groups/{group_id}/members/add \
  -H "Authorization: Bearer YOUR_API_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "contacts": [
      "14155551234",
      "447911123456",
      "5511987654321"
    ]
  }'

The contacts field accepts an array of phone number strings. MoltFlow validates and deduplicates automatically.

Step 4: Manage Group Membership

Once your group has members, you can manage them from the group detail page.

View Members List

Click on a group name from the Custom Groups page to see its full member list. The list shows:

Phone number (formatted for readability)
Date added to group
Actions (remove from group)

The list is paginated — you'll see 50 members per page with navigation at the bottom.

Remove Individual Contacts

To remove a single contact, click the "Remove" button next to their phone number in the member list.

This is useful when someone opts out of your messages or asks to be removed. Always honor opt-out requests immediately to maintain compliance and avoid spam reports.

Bulk Remove

To remove multiple contacts at once, select checkboxes next to the contacts you want to remove, then click "Remove Selected" at the top of the list.

Export Group to CSV

Need to back up your contacts or move them to another platform? Click "Export to CSV" on the group detail page.

MoltFlow generates a CSV file with all phone numbers in the group. The file format matches the import format, so you can re-import it later if needed.

Move Contacts Between Groups

To move contacts from one group to another:

Export the source group to CSV
Open the CSV in a spreadsheet app or text editor
Copy the phone numbers you want to move
Import them into the destination group using CSV import

Contacts can exist in multiple groups simultaneously — there's no restriction. For example, the same contact can be in "VIP Customers", "English Speakers", and "Newsletter Subscribers" all at once.

Step 5: Use Groups for Bulk Messaging

Now that you have organized contact groups, you can send targeted bulk messages.

Navigate to Dashboard > Outreach > Bulk Send and click "Create Campaign".

In the campaign creation form:

Select the target group from the dropdown
Compose your message
Configure throttling settings
Launch the campaign

All members of the selected group will receive your message, sent one by one at the rate you specified.

For detailed instructions on bulk messaging, see our send bulk messages guide.

You can also use groups with scheduled messages. When creating a scheduled message, you can target an entire group instead of a single phone number. Perfect for recurring newsletters, weekly updates, or monthly check-ins. Learn more in our schedule recurring messages guide.

Want to automatically add contacts from monitored WhatsApp groups? Check our monitor groups for leads guide.

Group Organization Tips

The power of WhatsApp contact groups lies in smart message segmentation. Here are proven ways to organize your contacts for maximum conversion:

By Purchase Intent (Sales Funnel)

Hot Leads — Requested pricing, scheduled a demo, asked specific questions
Warm Leads — Engaged with content, replied to initial outreach, showed interest
Cold Leads — In your database but haven't engaged yet

Send different messages to each segment. Hot leads get personalized follow-ups. Warm leads get educational content. Cold leads get broad awareness messages.

By Source (Attribution)

WhatsApp Group Leads — Captured from monitored groups
Website Signups — Came through your website contact form
Referrals — Introduced by existing customers
Event Attendees — Met at conferences, webinars, trade shows

Knowing where contacts came from helps you personalize your outreach and measure which sources convert best.

By Product Interest

Product A Interested — Asked about or purchased Product A
Product B Interested — Asked about or purchased Product B
Multi-product — Interested in multiple offerings

Send targeted product updates and cross-sell opportunities to the right segments.

By Language

English Speakers
Spanish Speakers
Portuguese Speakers

Always message people in their preferred language. Create separate campaigns for each language group.

By Time Zone

US East Coast — Send at 9 AM EST
US West Coast — Send at 9 AM PST
Europe — Send at 9 AM CET

Use scheduled messages with different send times for each group to ensure your message arrives during business hours.

By Customer Lifecycle Stage

Trial Users — Currently testing your product
Active Customers — Paying subscribers
Churned Customers — Cancelled or lapsed

Different segments need different messaging. Trial users get onboarding tips. Active customers get feature announcements. Churned customers get win-back offers.

The more specific your WhatsApp contact groups, the more relevant your messages, and the higher your engagement rates. MoltFlow groups are persistent and API-accessible — not just one-time broadcast lists that disappear after sending.

What's Next?

Now that you can organize contacts into custom groups for message segmentation, explore these related features:

Send Bulk Messages — Learn the full bulk send workflow with anti-spam best practices
Schedule Recurring Messages — Automate regular messages to your groups
Set Up Keyword Auto-Reply Rules — Automatically route contacts into groups based on keywords they send
Monitor WhatsApp Groups for Leads — Capture leads from WhatsApp groups and add them to custom contact groups

All of these features work together to create powerful, automated WhatsApp outreach workflows.

Ready to stop sending one-size-fits-all blasts and start using segmented campaigns that actually convert? Start your Growth trial and see how businesses increase conversion 3-5x with targeted WhatsApp contact groups.

Need help? Contact support via the dashboard chat or email us at [email protected]. We typically respond within 2-4 hours.

Create WhatsApp Contact Groups (3x Better Conversions)