Sending Invitations After Matching

Subtitle: How to Transition from Contact Discovery to Compliant Invitation Messaging

Once you match a contact, you might want to help users invite their friends to join.
But the moment you send a message, you move from passive discovery to active marketing communication.

Messaging matched contacts is heavily regulated and requires additional consent and transparency. This transition from matching to messaging triggers a different set of legal requirements that must be carefully addressed in your design and implementation.

This article explains how to design compliant invitation flows after matching, with specific guidance for creating interfaces and processes that respect both user intent and recipient rights.

Core Foundation

This article continues from:
Matching vs Messaging

Supporting articles:

• The Consent Playbook
• Post-Send Obligations

Why Messaging Requires Higher Standards

The transition from matching to messaging represents a significant shift in both user experience and legal requirements:

• Matching (Contact Discovery)

  • Surfacing matches silently only requires GDPR profiling protections
  • Typically can rely on legitimate interest or consent as lawful basis
  • Primarily governed by data protection regulations
  • Focused on internal processing and display

• Messaging (Sending Invitations)

  • Triggers marketing and anti-spam laws in addition to data protection regulations
  • Requires explicit consent in many jurisdictions
  • Creates direct communication with non-users
  • Involves sender reputation and deliverability concerns

Key Regulatory Frameworks:

• GDPR + PECR (EU/UK): Requires prior consent for most electronic marketing
• CAN-SPAM (USA): Requires clear identification and opt-out mechanisms
• CASL (Canada): Requires express consent with limited exceptions
• CPRA (California): Requires transparency about data sharing and incentives

Legal Principle: Messaging = Outreach = Regulation

This distinction is crucial because the penalties for non-compliant messaging can be significant, including regulatory fines, deliverability issues, and reputation damage.

How to Build Compliant Invite Flows

1. Make Sending Optional

The foundation of compliant invitation flows is user control and intentional action.

Implementation Guidance:

• User-Initiated Invitations

  • Let users manually trigger invites for specific contacts
  • Never send automatic messages without explicit user action
  • Separate matching from invitation functionality
  • Make invitation actions clear and deliberate

• Interface Design

  • Use explicit action buttons (e.g., “Invite Alex to join [Platform]”)
  • Avoid nudges or pressure to send invitations
  • Clearly distinguish between viewing matches and sending invites
  • Provide context about what happens when an invite is sent

Example Implementation:
After showing a match, present a clear, separate action button labeled “Invite to [Platform]” rather than automatically sending an invitation or using ambiguous language like “Connect.”

Legal Alignment:
This approach satisfies the “freely given” aspect of GDPR consent requirements and helps establish that the invitation was user-initiated rather than automatically generated by your platform.

2. Preview the Message

Transparency about what will be sent is essential for both user trust and legal compliance.

Implementation Guidance:

• Message Preview

  • Show the exact message before sending
  • Include all elements that will appear in the final message
  • Highlight who the invite is from and why
  • Display the recipient’s information

• Editable Content

  • Allow users to personalize the message when appropriate
  • Show character limits if applicable
  • Provide a default message that follows best practices
  • Indicate which parts can and cannot be modified

Example Preview Screen:

To: alex@example.com
From: you@example.com via [Platform]
Subject: [Your Name] invited you to join [Platform]

Message:
Hi Alex,

I'm using [Platform] and thought you might be interested in joining too.
[Optional personalized message from user]

[Platform] helps you [brief value proposition].

[Join button]

This is a one-time invitation. You won't receive follow-up messages unless you sign up.
[Company Name] | [Unsubscribe] | [Privacy Policy]

Legal Alignment:
This approach supports the “informed” aspect of consent under GDPR and creates transparency about the nature of the communication being sent.

3. Include Mandatory Disclosures

Invitation messages must include specific elements to comply with various marketing and privacy regulations.

Implementation Guidance:

Required Elements:

• Identify the sender (both the user and your platform)
• Explain why the invitee is receiving the message
• Provide a prominent, one-click opt-out mechanism
• Link to your privacy policy
• Include your company’s physical address (required by CAN-SPAM)
• Clarify that this is a one-time invitation

Message Structure:

• Clear subject line that identifies the purpose
• Brief, straightforward message body
• Visible footer with all required disclosures
• Prominent call-to-action
• Easy-to-find unsubscribe option

Example Disclosure Language:
“This invitation was sent by [Platform] on behalf of [User Name]. You received this message because [User Name] indicated they know you. This is a one-time invitation. [Platform] is located at [Address].”

Legal Alignment:
These disclosures satisfy requirements under CAN-SPAM, CASL, PECR, and GDPR for commercial electronic messages.

4. One-Time Messaging

Limiting the frequency of invitations is crucial for compliance with anti-spam regulations and maintaining recipient trust.

Implementation Guidance:

• Single Message Policy

  • Only send one invite per recipient unless they explicitly opt in to more
  • No reminders, no auto-follow-ups
  • Implement cooling-off periods before allowing resends
  • Track all sent invitations to enforce this policy

• Technical Implementation

  • Maintain a record of all sent invitations
  • Check against this record before allowing new invites
  • Hash recipient emails for privacy-preserving tracking
  • Implement global suppression checks

Exception Handling:

• If a user deletes and re-adds a contact, still enforce the one-time rule
• Consider time-based exceptions (e.g., allowing a new invite after 6-12 months)
• Document any exceptions to your one-time policy
• Require higher standards of consent for any follow-up messages

Legal Alignment:
This approach helps comply with CASL’s strict limitations on referral messages and reduces the risk of spam complaints under various regulations.

5. Record Consent and Invite Actions

Comprehensive logging creates accountability and provides evidence of compliance with privacy regulations.

Implementation Guidance:

Log These Elements:

• Sender user ID
• Recipient email hash (not the raw email)
• Timestamp of invitation
• Message version/template used
• Consent action (e.g., checkbox checked, button clicked)
• Opt-out events if any
• IP address of the sender (for verification purposes)

Technical Considerations:

• Store logs securely with appropriate access controls
• Implement tamper-evident logging mechanisms
• Maintain logs for the period required by applicable regulations
• Ensure logs can be accessed for regulatory inquiries

Documentation Approach:

• Create a data retention policy for invitation logs
• Document your logging implementation
• Establish processes for accessing logs when needed
• Include logging in your privacy impact assessment

Legal Alignment:
This approach satisfies the accountability principle under GDPR and provides evidence of compliance with various marketing regulations.

Best Practice Invite UX

Beyond compliance, well-designed invitation flows create better user experiences and higher conversion rates.

Implementation Guidance:

• Personalization Options

  • Let users personalize the message to make it more relevant
  • Provide a thoughtful default message as a starting point
  • Allow users to add context about why they’re inviting the person
  • Consider allowing users to select from message templates

• Respectful Messaging

  • Default to polite, low-pressure wording
  • Emphasize the one-time nature of the invitation
  • Focus on value rather than urgency
  • Avoid manipulative language or false scarcity

• Clear Expectations

  • Explain what happens after the invitation is sent
  • Clarify that you won’t send reminders
  • Indicate whether the user will be notified if their friend joins
  • Set realistic expectations about response time

Example Default Invite Text:
“I’ve been using [Platform] and thought you might find it valuable too. It helps with [key benefit]. This is just a one-time invitation—you’ll only hear from [Platform] again if you choose to sign up.”

Business Benefits:

• Higher conversion rates from quality invitations
• Reduced spam complaints and unsubscribes
• Better sender reputation and deliverability
• Stronger trust relationship with both users and recipients

Legal Requirements at a Glance

Different regions have specific requirements for invitation messages:

Region	Messaging Rules	Implementation Requirements
GDPR (EU/UK)	Prior consent before sending marketing messages	Explicit opt-in; clear identification; unsubscribe mechanism
CASL (Canada)	Express consent or strict “one-time referral” exception	Sender identification; unsubscribe mechanism; limited to one message
CPRA (California)	Disclosure if any incentives apply	Notice of financial incentive; opt-out of data sharing
CAN-SPAM (USA)	Clear sender identity + opt-out link	Physical address; accurate subject line; functioning unsubscribe
LGPD (Brazil)	Lawful basis for processing; transparency	Sender identification; purpose disclosure; opt-out mechanism

Global Compliance Strategy:

• Design for the strictest requirements (typically CASL and GDPR)
• Implement region-specific adjustments where necessary
• Document your compliance approach for each jurisdiction
• Regularly review and update as regulations evolve

For more detailed information on specific privacy laws, see: Other Privacy Laws

Risky Invitation Patterns to Avoid

Certain implementation patterns create significant legal and reputational risks:

Pattern	Risk	Better Alternative
Auto-sending invites to matched contacts	Marketing without consent; violation of multiple regulations	Require explicit user action to send invites; implement clear consent mechanisms
No opt-out link in invites	Breach of CAN-SPAM, GDPR, CASL; damages sender reputation	Include prominent, one-click unsubscribe in all communications
Sending reminders without opt-in	Triggers spam complaints; violates one-time messaging rules	Send only one message unless recipient explicitly opts in to more
Retargeting invitees in ads without disclosure	Privacy violation under CPRA; lack of transparency	Obtain specific consent for retargeting; provide clear disclosures
Pressuring users to send bulk invites	Creates poor-quality invitations; damages trust	Focus on quality over quantity; avoid gamification of invitation sending
Hiding the commercial nature of messages	Deceptive practice; violates transparency requirements	Clearly identify commercial nature; avoid misleading subject lines

Implementation Guidance:

• Conduct regular reviews of your invitation flows
• Test the recipient experience from different devices and email clients
• Monitor spam complaint rates and unsubscribe metrics
• Update your approach based on feedback and performance data

Summary: Invitation = Messaging = Respect Required

Effective invitation systems balance compliance requirements with user experience:

Action	Compliance Principle	Implementation Approach
Let users send, don’t auto-send	Freely given consent	User-initiated actions; clear, separate invitation buttons
Preview the message	Informed consent	Transparent preview screens; editable message content
Opt-outs honored immediately	Respect for non-user rights	One-click unsubscribe; global suppression list
Minimal data retention	Data minimization principle	Defined retention periods; purpose-limited processing
Clear sender identification	Transparency	Identify both user and platform; explain relationship
One-time messaging	Anti-spam compliance	No automatic reminders; cooling-off periods

If users feel proud to invite—and contacts feel respected receiving—the system works. The most effective invitation systems create a virtuous cycle where positive experiences lead to higher-quality connections and better engagement for everyone involved.

Up Next

Next, we’ll dive into how to engineer the contact import and matching system itself safely and legally.

Read Safe Contact Import

Or revisit matching vs messaging distinctions:
Matching vs Messaging