This guide will help you test your SMS functionality step-by-step before launching your app. No technical knowledge required, just follow the instructions and check that everything works as expected.

Why Testing is Important

Testing ensures your users will receive SMS messages correctly, your account won't be abused by bots, and your SMS balance won't drain unexpectedly. Think of it as a safety checklist before launch.

Pre-Testing Checklist

Before you begin, make sure you have:

☐ Access to your app (web or mobile)
☐ At least 2 different phone numbers for testing (yours and a friend's/colleague's)
☐ A phone that can receive Arabic messages (if your app supports Arabic)
☐ A notepad or document to record your test results
☐ Your developer available (in case something needs fixing)

Recommended SMS balance for testing: At least 20-30 SMS credits

Test 1: Basic SMS Sending (English)

What we're testing: Can your app send a basic English SMS successfully?

Steps:

  1. Open your app and navigate to where users can request an SMS (usually signup or login)
  2. Enter your phone number in this exact format: 96512345678 (country code + number, no + or 00 or spaces)
  3. Click the "Send SMS" or "Send Code" button
  4. Wait up to 60 seconds

What to expect:

  • ✅ You should receive an SMS within 30-60 seconds
  • ✅ The message should be clear and readable in English
  • ✅ The message should include your app/company name (e.g., "Your OTP for MYAPP is: 123456")
  • ✅ The code should be easy to copy (all numbers together)

What NOT to expect:

  • ❌ No message after 3 minutes
  • ❌ Gibberish or unreadable characters
  • ❌ Missing app name in the message
  • ❌ Message split into multiple parts when it should be one

Record your results:

  • Time sent: _______
  • Time received: _______
  • Message looks correct: Yes / No
  • App name included: Yes / No
If this test fails, stop and contact your developer before continuing.
Test 2: Arabic SMS Sending

What we're testing: Can your app send Arabic messages correctly?

Skip this test if your app doesn't support Arabic

Steps:

  1. Navigate to where you can trigger an SMS
  2. If your app allows custom messages, type a message in Arabic: مرحبا هذا اختبار
  3. If testing OTP only, check if your OTP message template includes Arabic
  4. Send the SMS to your phone number
  5. Wait up to 60 seconds

What to expect:

  • ✅ Arabic text appears correctly (not reversed or broken)
  • ✅ Characters are readable and make sense
  • ✅ Message arrives within 30-60 seconds

What NOT to expect:

  • ❌ Arabic text shows as ???? or boxes
  • ❌ Text appears reversed or scrambled
  • ❌ Characters are unreadable

Record your results:

  • Arabic displays correctly: Yes / No
  • Message readable on phone: Yes / No
Test 3: Phone Number Format Handling

What we're testing: Does your app accept different phone number formats and clean them properly?

Test 3A: Number with + prefix

Enter: +96512345678
Expected: SMS should still be sent successfully (app should remove the +)

Test 3B: Number with 00 prefix

Enter: 0096512345678
Expected: SMS should still be sent successfully (app should remove the 00)

Test 3C: Number with spaces

Enter: 965 1234 5678
Expected: SMS should still be sent successfully (app should remove spaces)

Test 3D: Number with dashes

Enter: 965-1234-5678
Expected: SMS should still be sent successfully (app should remove dashes)

Test 3E: Invalid numbers

Enter: 96522334455 (land line)
Expected: App should show an error message like "Invalid phone number" WITHOUT sending SMS

Test 3F: Invalid number format

Enter: 123456 (too short)
Expected: App should show an error message like "Invalid phone number" WITHOUT sending SMS

Test 3G: Accept International numbers (country codes handling)

Enter: 971504496677
Expected: App should show an error message like "Invalid phone number" WITHOUT sending SMS

Test 3H: Arabic/Hindi numbers

Enter: ٩٦٥١٢٣٤٥٦٧٨ (Arabic numerals)
Expected: App should show an error OR convert to English numbers automatically

Record your results:

For each test, mark: Passed / Failed

Test 4: OTP Code Verification

What we're testing: Can users enter the OTP code and verify successfully?

Steps:

  1. Request an OTP to your phone number
  2. Wait for the SMS to arrive
  3. Copy the code from the SMS
  4. Paste or type the code into your app
  5. Click "Verify" or "Submit"

What to expect:

  • ✅ Code is accepted and verification succeeds
  • ✅ You are logged in or moved to the next step
  • ✅ Success message appears

What NOT to expect:

  • ❌ "Invalid code" error when code is correct
  • ❌ Code doesn't work at all
  • ❌ Nothing happens when clicking verify

Test 4B: Wrong Code

Enter: 999999 (wrong code)
Expected: App shows "Invalid code" or similar error message

Test 4C: Expired Code

  1. Request an OTP
  2. Wait 4-5 minutes without entering it
  3. Try to use the code

Expected: App shows "Code expired" or similar message

Record your results:

  • Correct code works: Yes / No
  • Wrong code rejected: Yes / No
  • Expired code rejected: Yes / No
Test 5: Resend Functionality

What we're testing: Can users request a new code if they didn't receive the first one?

Steps:

  1. Request an OTP to your phone
  2. Wait at least 60 seconds
  3. Click the "Resend Code" or "Send Again" button
  4. Check your phone for a second SMS

What to expect:

  • ✅ A countdown timer shows before "Resend" becomes clickable (like "Resend in 45 seconds")
  • ✅ You cannot click "Resend" immediately (prevents spam)
  • ✅ After 60 seconds, "Resend" button becomes active
  • ✅ You receive a NEW code (different from the first)
  • ✅ The new code works for verification

What NOT to expect:

  • ❌ You can click "Resend" immediately with no wait time
  • ❌ No countdown timer visible
  • ❌ You receive the same code again
  • ❌ No second SMS arrives

Record your results:

  • Timer shows before resend: Yes / No
  • New code received: Yes / No
  • New code works: Yes / No
Test 6: Rate Limiting (Spam Prevention)

What we're testing: Can bots or abusers spam your SMS system?

Test 6A: Multiple Requests (Same Phone)

  1. Request an OTP to your phone number
  2. Immediately request another OTP to the same number
  3. Keep clicking "Send" 5-10 times rapidly

Expected:

  • ✅ After 3-5 attempts, you should see an error message like:
    • "Too many requests, please try again later"
    • "You've reached the limit, wait 1 hour"
    • "Please wait before requesting another code"
  • ✅ No more SMS messages are sent to your phone
If all 10 SMS are sent: ⚠️ CRITICAL ISSUE - Your app has no rate limiting! Contact your developer immediately.

Test 6B: Multiple Requests (Different Phones)

You'll need 6-7 different phone numbers for this test

  1. From the same device/computer, send OTP to phone number 1
  2. Send OTP to phone number 2
  3. Send OTP to phone number 3
  4. Continue until phone number 6-7

Expected:

  • ✅ After 3-5 different numbers, you should see an error message
  • ✅ The system blocks further requests
If all 7 SMS are sent: ⚠️ WARNING - Your app might be vulnerable to balance drainage attacks.

Record your results:

  • Same phone limit works: Yes / No
  • Multiple phone limit works: Yes / No
  • Error message appears: Yes / No
Test 7: CAPTCHA Verification

What we're testing: Does your app have bot and automation tools protection?

Steps:

  1. Navigate to the SMS request page (signup/login)
  2. Before entering any information, look for a CAPTCHA

What to expect:

✅ You see one of these:

  • "I'm not a robot" checkbox (reCAPTCHA)
  • Image puzzle to solve
  • "Check this box" verification
  • Invisible CAPTCHA (badge in corner of screen)

Test the CAPTCHA:

  1. Complete the CAPTCHA verification
  2. Request an SMS
  3. Verify the SMS is sent only AFTER completing CAPTCHA

What NOT to expect:

  • ❌ No CAPTCHA anywhere on the page
  • ❌ SMS is sent without completing CAPTCHA
  • ❌ CAPTCHA appears but doesn't actually block bots
If there's no CAPTCHA: ⚠️ CRITICAL SECURITY ISSUE - Bots can drain your balance!

Record your results:

  • CAPTCHA present: Yes / No
  • CAPTCHA must be completed before SMS: Yes / No
  • Type of CAPTCHA: _______________
Test 8: Error Messages

What we're testing: Does your app show clear, helpful error messages?

Test 8A: No Internet Connection

  1. Turn off your internet/WiFi
  2. Try to request an SMS

Expected: Clear message like "No internet connection" or "Please check your connection"

Test 8B: Invalid Phone Format

  1. Enter: abc123xyz
  2. Click send

Expected: Message like "Please enter a valid phone number"

Test 8C: Empty Phone Number

  1. Leave phone field blank
  2. Click send

Expected: Message like "Phone number is required"

Test 8D: Server Error (Ask developer to simulate)

Expected: Message like "Something went wrong, please try again" (not technical error codes)

Record your results:

Test Shows Error Message Message is Clear
No Internet Yes / No Yes / No
Invalid Format Yes / No Yes / No
Empty Field Yes / No Yes / No
Server Error Yes / No Yes / No
Test 9: Special Characters and Emojis

What we're testing: Does your app handle special characters safely?

Skip this test if your app only sends pre-defined OTP messages

Test 9A: Emojis

If your app allows custom messages:

  1. Type a message with emojis: "Hello 😊👍🎉"
  2. Send the SMS

Expected:

  • ✅ App removes emojis and sends: "Hello"
    OR
  • ✅ App shows error: "Emojis not supported"

NOT expected:

  • ❌ SMS fails to send with no error message
  • ❌ Message shows as gibberish

Test 9B: Special Characters

  1. Type: "Test @#$%^&*() message"
  2. Send the SMS

Expected:

  • ✅ Message arrives with special characters intact OR cleaned
  • ✅ Message is readable

Record your results:

  • Emojis handled correctly: Yes / No
  • Special characters handled: Yes / No
Test 10: Balance Tracking (Developer Check)

What we're testing: Is your SMS balance being tracked correctly?

Ask your developer to check:

  1. Check your current SMS balance
  2. Send 3 test messages
  3. Check balance again

Developer should confirm:

  • ✅ Balance decreased by 3 (or the correct amount for your SMS type)
  • ✅ Each SMS cost is recorded
  • ✅ Balance updates after each send

If balance doesn't change or decreases incorrectly: Contact your SMS provider and developer.

Test 11: Load Test (Optional but Recommended)

What we're testing: Can your app handle multiple users at once?

You'll need 3-5 friends/colleagues with phones

Steps:

  1. Ask everyone to open your app at the same time
  2. Everyone requests an OTP at the exact same moment (use countdown: 3, 2, 1, GO!)
  3. Wait for all SMS to arrive

What to expect:

  • ✅ All SMS are sent successfully
  • ✅ All SMS arrive within 1-2 minutes
  • ✅ No one gets an error message
  • ✅ No one's SMS is "stuck"

What NOT to expect:

  • ❌ Some SMS never arrive
  • ❌ Error messages appear
  • ❌ App crashes or becomes unresponsive

Record your results:

  • Total people testing: _____
  • SMS received successfully: _____
  • Any failures: Yes / No

Critical Issues Checklist

These issues MUST be fixed before launch:

Issue Status Priority
SMS not arriving ☐ 🔴 CRITICAL
Gibberish in messages ☐ 🔴 CRITICAL
No rate limiting (can spam unlimited) ☐ 🔴 CRITICAL
No CAPTCHA (bot vulnerable) ☐ 🔴 CRITICAL
App name missing from OTP ☐ 🟡 HIGH
Can't handle different phone formats ☐ 🟡 HIGH
No error messages shown ☐ 🟡 HIGH
OTP doesn't expire ☐ 🟡 HIGH
Can resend immediately (no timer) ☐ 🟠 MEDIUM
Arabic not working ☐ 🟠 MEDIUM

Final Testing Checklist

Before you approve the app for launch, confirm:

☐ ✅ English SMS sent and received successfully
☐ ✅ Arabic SMS working (if applicable)
☐ ✅ All phone number formats accepted and cleaned
☐ ✅ OTP verification working correctly
☐ ✅ Wrong/expired codes are rejected
☐ ✅ Resend timer working (60+ seconds)
☐ ✅ Rate limiting active (can't spam)
☐ ✅ CAPTCHA present and working
☐ ✅ Clear error messages shown
☐ ✅ Special characters/emojis handled
☐ ✅ Multiple users can send simultaneously
☐ ✅ SMS balance tracking correctly

What to Do If Tests Fail

Minor Issues (🟠 MEDIUM Priority)

  • Document the issue with screenshots
  • Share this document with your developer
  • Schedule a fix before launch

Major Issues (🟡 HIGH Priority)

  • Do not launch until fixed
  • Have developer fix within 1-2 days
  • Re-test after fix

Critical Issues (🔴 CRITICAL Priority)

  • STOP ALL LAUNCH PLANS
  • Fix immediately before any further testing
  • This could cost you money or damage user trust
  • Re-test completely after fix

Test Results Summary Template

Copy this template and fill it out:

SMS API Testing Results
===================================
Date: _______________
App Version: _______________
Tester Name: _______________
PASSED TESTS:




FAILED TESTS:




CRITICAL ISSUES FOUND:



READY FOR LAUNCH: YES / NO
NOTES:


_________________________________

Questions to Ask Your Developer

If something isn't clear during testing, ask your developer:

  1. "What happens if a user requests 10 OTP codes in 1 minute?"
  2. "How long does an OTP code stay valid?"
  3. "What's our daily SMS sending limit?"
  4. "Do we have monitoring in place to detect unusual SMS activity?"
  5. "What happens if our SMS balance runs out?"
  6. "Can users report not receiving SMS, and how do we investigate?"

Monthly Monitoring Checklist

After launch, check these monthly:

☐ Review SMS sending volume for unusual spikes
☐ Check SMS balance and refill before it runs out
☐ Review any user complaints about SMS not arriving
☐ Verify rate limiting is still working
☐ Check SMS delivery success rate (should be >95%)

Need Help?

If you find issues during testing:

  1. Document everything: Take screenshots, note exact error messages
  2. Share this completed checklist with your developer
  3. Don't launch until critical issues are resolved
  4. Re-test everything after fixes are made

Remember: It's better to delay launch and get it right than to launch with SMS problems that will frustrate users and cost you money.

Good luck with your testing! 🚀