Reminders are among the cheapest interventions available and they are frequently implemented in a way that guarantees they do nothing.
Channel
Text messages are read within minutes by nearly everybody. Email is read eventually by some people. Voicemail is largely not listened to at all.
For anything time-sensitive, text. Use email for anything that needs length, attachments or a record. Use both where the stakes justify it.
Timing
Too early and it is filed and forgotten. Too late and it arrives after the person has made other plans.
For an appointment, a short sequence works better than a single message: confirmation on booking, something a few days out, something the day before or the morning of. Each one is a chance to catch somebody whose plans have changed.
For a deadline or a renewal, work backwards from how long the person actually needs to act, and add margin.
Wording
- Lead with the specific. Date, time, place, in the first line. Not a greeting and a paragraph of context.
- Say what they need to do, if anything. "Nothing needed, just turn up" is a useful sentence.
- Give one action. Confirm, or reschedule. Two links, not seven.
- Sound like a person from the business, not like a notification. That is a wording choice, not a technology choice.
- Keep it short. A long reminder is skimmed and the important bit is missed.
Make it two-way
A reminder somebody cannot reply to is a reminder that gives them no option when their plans have changed. That is how you convert a reschedule into a no-show.
Replies should reach somebody, and common replies (confirm, cancel, reschedule) should be handled automatically.
Stop when they have acted
The fastest way to make a system feel broken is to keep reminding somebody about something they have already done. Anything that continues after the action was taken damages trust in every message you send.
Frequency
More is not better past a point. Three well-timed messages beat six, and six starts producing opt-outs. If people are unsubscribing or replying with irritation, the sequence is too long or too generic.