Best Practices for SMS Delivery and Compliance

Ensure your messages deliver reliably while respecting regulations and recipient preferences #

SMS marketing and notifications are highly effective, but they come with responsibilities. Following best practices for SMS delivery and compliance isn’t just about avoiding legal trouble—it’s about building trust with your audience, maintaining deliverability, and creating positive experiences that strengthen your relationships. From obtaining proper consent to crafting concise, valuable messages, these guidelines help you leverage SMS’s power while respecting your recipients’ time and privacy.

Understanding and implementing SMS best practices protects your reputation, improves delivery rates, reduces costs, and keeps you compliant with regulations across different countries and regions. Whether you’re sending a handful of appointment reminders or thousands of marketing messages, these principles ensure your SMS strategy is sustainable, effective, and respectful.

Consent and Opt-In Requirements #

Always Get Permission First #

Never send SMS messages without explicit consent from recipients. This is both a legal requirement in most jurisdictions and a fundamental respect for people’s privacy.

How to Obtain Consent:

• Explicit Checkbox: Add a clear checkbox on your form: “I agree to receive SMS messages”
• Double Opt-In: Consider confirming consent with a confirmation message requiring a reply
• Clear Language: Explain what types of messages they’ll receive and how often
• Easy Opt-Out: Always provide a simple way to stop receiving messages
• Record Keeping: Maintain records of when and how consent was obtained

Consent Best Practices:

• Be specific about message frequency (e.g., “up to 5 messages per month”)
• Explain the purpose (e.g., “appointment reminders” or “order updates”)
• Include opt-out instructions at the point of consent
• Don’t use pre-checked boxes—require active consent
• Honor opt-outs immediately (within minutes, not days)

Respect Opt-Out Requests #

When someone asks to stop receiving messages, honor that request immediately and completely.

Standard Opt-Out Methods:

• STOP Command: Accept replies of “STOP”, “UNSUBSCRIBE”, “CANCEL”, “END”, or “QUIT”
• Confirmation: Send a final message confirming they’ve been unsubscribed
• No More Messages: Ensure no additional messages are sent after opt-out
• Documentation: Keep records of opt-out requests and dates

Example Opt-Out Language:

Reply STOP to unsubscribe from these messages.

Message Content Guidelines #

Keep Messages Concise and Valuable #

SMS is inherently limited, so every character counts. Focus on delivering value quickly.

Message Length Best Practices:

• Aim for 160 Characters: Standard SMS limit; exceeding it splits messages and increases costs
• Front-Load Important Info: Put the most critical information first
• One Clear Action: Each message should have one primary purpose or call-to-action
• Avoid Fluff: Skip unnecessary pleasantries and get to the point
• Use Abbreviations Carefully: Only use universally understood abbreviations

Character Considerations:

• Regular characters count as 1
• Some special characters count as 2
• Emojis can count as multiple characters
• Line breaks count as characters
• URLs should be shortened to save space

Provide Clear Value #

Every message should offer something worthwhile to the recipient.

Valuable Message Types:

• Order confirmations and shipping updates
• Appointment reminders with booking details
• Time-sensitive alerts and notifications
• Account security notifications
• Exclusive offers or time-limited discounts
• Event updates and last-minute changes
• Survey results or quiz scores

Avoid:

• Generic promotional messages without offers
• Frequent “just checking in” messages
• Information readily available elsewhere
• Multiple messages when one would suffice

Identify Your Organization #

Recipients should immediately know who’s messaging them.

Identification Best Practices:

• Start with Brand Name: Begin messages with your organization name
• Consistent Sender ID: Use the same from-number or sender ID consistently
• Clear Context: Reference the relationship (e.g., “your recent order” or “your appointment with…”)

Example:

FORMEPIC: Your appointment on May 15 at 2 PM is confirmed. Reply YES to confirm or NO to reschedule.

Timing and Frequency #

Respect Recipient Time Zones #

Don’t wake people up or message during inconvenient hours.

Time-Based Best Practices:

• Safe Hours: Send between 9 AM – 8 PM in recipient’s local time zone
• Avoid Weekends: Unless relevant (event reminders, time-sensitive alerts)
• Consider Context: B2B messages during business hours; consumer messages in evenings
• Holiday Awareness: Skip major holidays unless the message is holiday-related
• Time Zone Data: Collect or infer time zones to schedule appropriately

Limit Message Frequency #

Too many messages lead to opt-outs and damage your relationship.

Frequency Guidelines:

• Transactional Messages: Send as needed (confirmations, alerts)
• Marketing Messages: Maximum 3-4 per month unless explicitly agreed otherwise
• Digest Over Individual: Use digests to batch updates rather than sending each individually
• Respect User Preferences: Allow recipients to choose frequency
• Monitor Opt-Outs: Rising opt-out rates signal you’re messaging too frequently

Schedule Strategically #

Timing affects open rates and response rates significantly.

Optimal Send Times:

• Morning (9-11 AM): Good for reminders and action-requiring messages
• Lunch (12-1 PM): Catch people checking phones during breaks
• Evening (5-8 PM): Personal time when people are receptive
• Avoid Early Morning: Before 9 AM feels intrusive
• Avoid Late Night: After 8 PM can be disruptive

Deliverability Best Practices #

Use a Dedicated Number #

Shared shortcodes and numbers can hurt deliverability if others abuse them.

Number Best Practices:

• Dedicated Number: Use your own number for consistent sender identity
• Local Numbers: Consider local area codes for your primary audience
• Verify Number: Always verify your number with your SMS provider
• Consistent Sender: Don’t rotate numbers unnecessarily
• Branded Sender ID: Where available (outside US), use branded sender IDs

Maintain List Hygiene #

Clean, accurate contact lists improve delivery rates and reduce costs.

List Management:

• Validate Phone Numbers: Check format before sending
• Remove Bounces: Delete numbers that bounce or fail repeatedly
• Update Contacts: Keep contact information current
• Remove Duplicates: Don’t message the same person twice
• Regular Cleaning: Review and clean lists quarterly

Monitor Delivery Metrics #

Track performance to identify and fix issues quickly.

Key Metrics to Monitor:

• Delivery Rate: Percentage of messages successfully delivered
• Bounce Rate: Failed deliveries (should be under 5%)
• Opt-Out Rate: Unsubscribe rate (should be under 2%)
• Response Rate: For messages requiring action
• Carrier Filtering: Messages marked as spam

Avoid Spam Triggers #

Certain content patterns can trigger carrier spam filters.

Spam Triggers to Avoid:

• ALL CAPS MESSAGES
• Excessive punctuation!!!!!
• Too many emojis 🎉🎊🎁💰
• Suspicious links or shortened URLs from untrusted services
• Phrases like “FREE!!!”, “ACT NOW!!!”, “LIMITED TIME!!!”
• Messages that look like typical spam

Compliance and Legal Requirements #

Know Your Regulations #

Different countries and regions have different SMS regulations.

Key Regulations:

• TCPA (US): Telephone Consumer Protection Act requires prior express consent
• CAN-SPAM (US): Applies to commercial SMS messages
• GDPR (EU): European data protection and consent requirements
• CASL (Canada): Canadian anti-spam legislation covering SMS
• Industry-Specific: Healthcare (HIPAA), financial services, etc.

Required Message Elements #

Most jurisdictions require certain information in SMS messages.

Compliance Checklist:

• [ ] Organization identification (who you are)
• [ ] Opt-out instructions (how to stop messages)
• [ ] Clear purpose (why they’re receiving the message)
• [ ] Contact information (how to reach you)
• [ ] Consent records (proof they agreed)

Example Compliant Message:

FORMEPIC: Your order #12345 shipped today! Track: [link]. Questions? Call 555-0100. Reply STOP to opt out.

Data Protection and Privacy #

Handle phone numbers and personal data with care.

Privacy Best Practices:

• Secure Storage: Encrypt phone numbers and personal data
• Limited Access: Restrict who can access contact lists
• Data Minimization: Only collect data you actually need
• Retention Policies: Delete old data you no longer need
• Third-Party Sharing: Never sell or share contact lists
• Breach Response: Have a plan for responding to data breaches

Industry-Specific Compliance #

Healthcare (HIPAA):

• Don’t include protected health information (PHI) in messages
• Use generic language: “You have a message from Dr. Smith” not diagnoses
• Ensure SMS provider is HIPAA-compliant with BAA
• Consider patient consent specifically for SMS communication

Financial Services:

• Avoid account numbers or sensitive financial data in SMS
• Use secure authentication for financial transactions
• Comply with regulations like GLBA
• Be extra cautious about security

Marketing and Advertising:

• Follow FTC guidelines for advertising
• Clearly identify promotional content
• Honor Do Not Call registry where applicable
• Be transparent about sponsored content

Technical Best Practices #

Use International Format #

Always format phone numbers consistently for reliable delivery.

Formatting Standard:

• Start with + sign
• Include country code
• Include area/regional code
• Include local number
• No spaces, dashes, or parentheses

Examples:

• US: +12025551234 (not 202-555-1234)
• UK: +447700900123 (not 07700 900123)
• AU: +61412345678 (not 0412 345 678)

Implement Retry Logic #

Messages sometimes fail to deliver on first attempt.

Retry Best Practices:

• Retry Failed Messages: Attempt redelivery 2-3 times
• Exponential Backoff: Wait increasingly longer between retries (5min, 30min, 2hr)
• Limit Retries: Stop after 3 attempts to avoid annoying recipients
• Track Failures: Log why messages failed for analysis
• Notify Admins: Alert administrators about persistent delivery failures

Use URL Shorteners Wisely #

Long URLs waste characters and look unprofessional.

URL Best Practices:

• Reputable Shorteners: Use trusted services like Bitly, not suspicious domains
• Branded Links: Consider branded short domains (yourbrand.co/…)
• Track Clicks: Use shortener analytics to track engagement
• Test Links: Always verify shortened URLs work before sending
• HTTPS Only: Only use secure HTTPS links
• Descriptive: Give context before the link so people know what they’re clicking

Monitor Provider Health #

Keep track of your SMS provider’s performance and status.

Provider Monitoring:

• Check provider status pages for outages
• Review delivery reports regularly
• Monitor account balance and billing
• Track provider-specific metrics
• Have a backup provider for critical messages
• Stay updated on provider policy changes

Content Personalization Best Practices #

Personalize Appropriately #

Personalization increases engagement, but overdoing it feels creepy.

Good Personalization:

• First name in greeting
• Relevant order/appointment details
• Location-specific information
• Recent activity context

Avoid:

• Too much personal detail (looks like you’re tracking heavily)
• Incorrect personalization (worse than none)
• Personal information that shouldn’t be in SMS (SSN, full address)

Dynamic Fields Usage #

Use form data effectively without overwhelming the message.

Best Practices:

• Use 2-3 dynamic fields maximum per message
• Always have fallback values for empty fields
• Test that fields populate correctly
• Use fields that add value, not just for the sake of it

Cost Optimization #

Reduce Message Splitting #

Keep messages under 160 characters to avoid split charges.

Cost-Saving Tips:

• Count characters before sending
• Use URL shorteners
• Abbreviate where appropriate (but stay clear)
• Remove unnecessary words
• Consider sending shorter, more frequent updates instead of long messages

Choose the Right Message Type #

Use the most cost-effective message type for each scenario.

Cost Considerations:

• Notifications: Pay per message, use for urgent alerts
• Autoresponders: Pay per recipient, good ROI for confirmations
• Digests: One message per period, cost-effective for summaries

Monitor and Optimize #

Track costs and adjust strategy based on ROI.

Optimization Strategies:

• Review provider costs monthly
• Compare provider pricing for your volume
• Identify unnecessary messages to eliminate
• A/B test message frequency
• Calculate ROI per message type
• Consider bulk pricing or contracts for high volume

Testing and Quality Assurance #

Test Everything #

Never send to your full list without thorough testing.

Testing Checklist:

• Send test messages to yourself first
• Test on multiple carriers
• Verify personalization fields populate
• Check message length and splitting
• Test opt-out functionality
• Verify links work and track correctly
• Test in different time zones if relevant

Monitor Results #

Track performance to continuously improve.

Key Performance Indicators:

• Open rates (SMS is typically 98%+)
• Click-through rates for links
• Opt-out rates (should be under 2%)
• Response rates for interactive messages
• Delivery failures and bounces
• Conversion rates for marketing messages

Tips and Tricks #

• Build Trust Gradually: Start with valuable transactional messages before marketing
• Segment Your Audience: Send relevant messages to relevant people
• A/B Test: Try different messages, times, and frequencies
• Mobile-First Mindset: Remember recipients are on mobile—keep it simple
• Human Tone: Write conversationally, not robotically
• Clear CTAs: Make it obvious what action you want them to take
• Respect Context: Different relationships warrant different messaging styles
• Learn from Opt-Outs: If someone opts out, ask why (optional survey)
• Celebrate Milestones: Use SMS for special occasions (birthdays, anniversaries)
• Emergency Protocol: Have a plan for urgent mass notifications

Important Notes #

• Compliance is Non-Negotiable: Legal violations can result in significant fines
• Trust is Fragile: One bad experience can lose a customer forever
• Deliverability Matters: Poor practices can get your number blocked
• ROI Over Volume: Quality, targeted messages outperform high-volume spam
• Documentation: Keep records of consent, opt-outs, and compliance efforts
• Stay Updated: SMS regulations and best practices evolve—review annually
• Provider Terms: Follow your SMS provider’s terms of service strictly
• Global Differences: What works in one country may be illegal in another
• Cost Adds Up: SMS costs can escalate quickly with high volume

Common Issues & Troubleshooting #

High Opt-Out Rates

• You’re messaging too frequently
• Content isn’t valuable enough
• Messages are going to the wrong audience
• Poor timing (late night, early morning)
• Fix: Survey opt-outs to understand why, adjust frequency and content

Low Delivery Rates

• Invalid phone numbers in your list
• Carrier filtering messages as spam
• Provider issues or account problems
• Number not verified with provider
• Fix: Clean list, avoid spam triggers, check provider status

Messages Marked as Spam

• Using spam trigger words or formatting
• Sending from unverified numbers
• Too high volume too quickly
• Recipients reporting messages
• Fix: Review content, slow send rate, improve targeting

Regulatory Violations

• Sending without consent
• Missing opt-out instructions
• Messaging outside allowed hours
• Not honoring opt-out requests
• Fix: Audit all messages for compliance, implement proper consent workflows

Poor ROI

• Messages not leading to desired actions
• Wrong audience or poor segmentation
• Unclear calls-to-action
• Value proposition unclear
• Fix: A/B test messages, improve targeting, clarify benefits

Carrier Blocking

• Too many spam complaints
• High opt-out rates
• Violating carrier policies
• Using suspicious content
• Fix: Contact provider, review practices, request carrier review

By following these best practices, you’ll build a sustainable, effective SMS strategy that respects your recipients, complies with regulations, and delivers real value to your audience and your organization.