Everyone agrees that reminders work. The debate is always about when to send them. Too early and the customer ignores it — the appointment feels too far away to act on. Too late and they've either already booked elsewhere or let it lapse. The window between "too early" and "too late" is narrower than most people think.
This article is based on reminder performance data from over 1,500 UK garages using My Garage CRM. Not theory — actual send times, intervals, channels and conversion rates from millions of reminders across MOTs, annual services, interim services and seasonal promotions. The patterns are clear and consistent regardless of garage size or location.
The Three Timing Zones
Every reminder falls into one of three zones. The zone determines whether it converts, gets ignored, or actively annoys the customer:
Single Message vs Multi-Touch — The Data Is Not Close
The most common mistake garages make with reminders is sending one message and hoping for the best. The data shows exactly how much that costs:
A three-message sequence converts at more than double the rate of a single message. That's not a marginal improvement — it's the difference between losing most of your MOT customers and retaining most of them. The additional two messages cost pennies to send and require zero manual effort.
Why three messages work
- 6 weeks — the planner — approximately 30% of customers book within 48 hours of the first reminder. These are organised people who appreciate advance notice and like to schedule things early.
- 2 weeks — the intender — approximately 25% of customers book at this stage. These people saw the first message, meant to act, and needed a nudge. The 2-week mark creates real urgency without panic.
- 3 days — the procrastinator — approximately 12% book at the final reminder. These customers will never act until the last possible moment. Without this message, they lapse entirely.
Conversion Rate by Interval — The Full Data
Here's the booking conversion rate at every common interval, based on single-message reminders (to isolate the effect of timing alone):
The peak single-message conversion is at 4 weeks (32%), with strong performance from 2–6 weeks. After the due date, conversion drops dramatically — once the MOT or service has lapsed, the urgency evaporates and the customer is more likely to have already gone elsewhere or decided to delay indefinitely.
SMS vs Email — Which Channel Converts?
SMS
SMS outperforms email on every metric except cost. But the answer isn't "use SMS and skip email" — it's "use both." The two channels reach different customer segments. Some customers read texts immediately and never check email. Others have their phone on silent but check email hourly. Dual-channel reminders have a 23% higher total conversion rate than SMS alone.
Best Day and Time to Send
Send timing affects open rate and — more importantly — click-through rate. Here's the performance heatmap across weekdays and time slots:
The peak conversion window is Tuesday–Wednesday between 9am and noon. This makes sense: customers have settled into their week, they're at their desk or on a break, and they have enough days ahead to call or book online. Friday afternoons and weekends show the lowest conversion — customers are mentally checked out and defer action to next week (and then forget).
The evening slot (6–9pm) shows surprisingly strong performance on Tuesday evenings specifically. This likely reflects customers who read the morning SMS but didn't act, then circle back when they're home and have time to check their calendar and book.
Recommended Intervals by Service Type
Different services need different reminder sequences. An MOT has a fixed deadline — a service reminder is more flexible. Here's what works for each:
| Service Type | First Reminder | Second Reminder | Final Reminder | Channel |
|---|---|---|---|---|
| MOT | 6 weeks before expiry | 2 weeks before | 3 days before | SMS + Email → SMS + Email → SMS only |
| Full / major service | 11 months after last service | 11.5 months | 12 months | SMS + Email → SMS + Email → SMS only |
| Interim service | 5.5 months after last service | 6 months | — | SMS + Email → SMS only |
| Seasonal check (winter/summer) | 4 weeks before season start | 1 week before | — | SMS only (promotional) |
| Advisory follow-up | 7 days after MOT | 21 days after MOT | — | SMS + Email → SMS only |
Notice that service reminders are timed from the last visit date rather than a fixed expiry date. This means the system needs to track when each customer last had a service — not just their MOT date. A CRM that only tracks MOT dates misses the entire service reminder opportunity.
The Compound Effect of Good Timing
When interval, channel and send time are all optimised, the effect compounds. Here's the difference between a poorly timed reminder and a well-timed sequence across 100 customers:
- One email, 4 weeks before, sent Friday afternoon — approximately 3 bookings (3% conversion). The email is buried in inboxes, sent at the worst time, with no follow-up.
- Three-message SMS + email sequence, 6w/2w/3d, sent Tuesday 9am — approximately 67 bookings (67% conversion). Every variable optimised. Same 100 customers. 22x more bookings.
The difference isn't caused by one factor — it's the combination of the right channel (SMS), the right intervals (6w/2w/3d), the right send time (Tuesday morning) and the right frequency (three touchpoints). Each factor multiplies the others. Get them all right and the result is transformative.
What This Means for Your Garage
If you're currently sending one reminder (or none), the improvement available is enormous — and it's achievable with no additional staff, no additional hours, and minimal setup. The automation runs in the background, fires at the optimal time, and fills the diary without anyone touching it.
The data in this article isn't aspirational. It's what's already happening in 1,500+ UK garages right now. The only variable is whether your garage is one of them.