The debate seems simple: SMS or email for customer reminders? But the answer matters more than you'd think. The wrong choice means your carefully crafted messages disappear into the void, unseen and unbooked.
Let's look at actual data, real costs, and what works in practice for NZ workshops.
97%
SMS Open Rate
Most opened within 3 minutes of delivery
20%
Email Open Rate
Industry average for service businesses
Those numbers tell part of the story. But open rate isn't everything - let's dig deeper.
The Full Comparison
| Factor | SMS | |
|---|---|---|
| Open rate | 97% | 15-25% |
| Read time | Under 3 minutes | Hours to days |
| Cost per message | 10-15 cents | Essentially free |
| Message length | 160 characters ideal | Unlimited |
| Images/branding | No (MMS expensive) | Yes - full branding |
| Links | Yes (shortened) | Yes (buttons, multiple) |
| Spam filtering | Very low risk | Moderate risk |
| Reply capability | Easy - just reply | Often ignored |
When to Use SMS
SMS wins for time-sensitive, action-required messages:
Perfect for SMS
- WOF expiry reminders (2 weeks, 3 days)
- Booking confirmations
- "Your car is ready" notifications
- Additional work approval requests
- Payment reminders
SMS Template Example
"Hi Sarah, your Mazda 3's WOF expires 15 March - 2 weeks away! Book now: hoistapp.co/book or reply YES and we'll call you. - ABC Motors"
142 characters - fits in one SMS
When to Use Email
Email works better for informational, detailed communications:
Perfect for Email
- Detailed quotes with line items
- Invoices with full breakdown
- Early service reminders (4+ weeks)
- Newsletters and promotions
- Vehicle inspection reports with photos
Email Advantage
Email lets you include your logo, brand colours, multiple photos, detailed breakdowns, and multiple calls-to-action. It's your digital letterhead - professional and informative.
The Best Approach: Use Both
Don't choose one or the other. Use both strategically:
Example: WOF Reminder Sequence
4 weeks before - Email
Detailed reminder with your branding, service options, link to book online
2 weeks before - SMS
Urgent, personal reminder with specific expiry date and easy booking link
3 days before - SMS
"Last chance" reminder creating urgency
Cost Reality Check
SMS costs add up. Here's realistic budgeting:
Monthly SMS Costs
- 500 customers × 2 reminders = 1,000 SMS
- 1,000 × $0.12 = $120/month
Worth it if even 10 extra bookings result (~$2,000 revenue)
Email Costs
- Unlimited emails in most plans
- Cost: $0 (included in software)
Use freely for early reminders, newsletters, and detailed comms
ROI Perspective
If $120/month in SMS costs generates 10 extra bookings at $200 average = $2,000 revenue. That's a 16x return. The question isn't whether SMS is worth the cost - it's whether you're using it effectively enough.
Common Mistakes to Avoid
Sending novels via SMS
SMS should be short and punchy. If your message needs more than 160 characters, consider email for the details and SMS for the nudge.
Being vague in either channel
"Your service might be due" gets ignored. Specific dates and actions ("WOF expires 15 March - book now") get results.
Sending too many messages
4 reminders max for any one service. More than that crosses from helpful to annoying. You'll get unsubscribes and damage relationships.
No clear call-to-action
Every message needs an obvious next step: "Book now at [link]" or "Reply YES to confirm." Don't make them figure it out.
The Bottom Line
SMS and email aren't competitors - they're complementary tools. Use email for detailed, early communications where cost matters and urgency doesn't. Use SMS when you need immediate attention and action.
The workshops winning at customer communication use both strategically. SMS open rates of around 97-98% (a widely-cited industry benchmark) are powerful, but only if you're sending the right message at the right time.
Start with a simple sequence: email at 4 weeks, SMS at 2 weeks and 3 days. Measure results. Adjust from there.