Outage email to customers: templates and what to leave out
When your service has been down, the email you send is read by people who lost time, and some of them will forward it to their boss. This page gives you three short templates (a heads-up during the outage, an all-clear, and a cover note for a full report), a rule for the subject line, and a list of the sentences that cause trouble later. The incident in the examples is invented.
Which email, when
- During the outage: only for customers who are directly affected and who cannot see your status page. Keep it to four sentences. If a status page exists, link it and use the status page update templates instead of writing a second text.
- After service is restored: a short all-clear within a day, with the start and end times and one line on what happens next.
- With the full report: a cover note that puts the three facts a customer wants in the first lines and attaches or links the report.
Subject lines
Say what happened to the customer, in their words, with the date. Good: "Booking was unavailable on 3 Oct, 09:12 to 09:48 UTC". Weak: "Important service notice" (it reads like marketing) and "RCA for INC-2291" (it means nothing to a customer who never saw your ticket number).
Template 1: heads-up during the outage
Subject: [Feature] is unavailable right now ([date]) Hello [first name], Since about [time and zone], [feature] has not been working for some customers, including your account. You may see [what they will notice]. We are working on it and will email you again by [time and zone], even if there is nothing new to say. Live updates are at [status page link]. [Name], [company]
Do not guess a cause or a fix time here. "Since about" is honest when you only know when you noticed.
Template 2: all-clear
Subject: [Feature] is working again: it was unavailable [start] to [end] on [date] Hello [first name], [Feature] has been working normally since [time and zone]. It was unavailable from [start] to [end] ([duration]), and [what it meant for them, for example "bookings made in that window were not saved"]. [One sentence on the cause, only if it is confirmed. Otherwise: "We are still confirming the cause."] We will send you a full report by [date]. If you were affected in a way not covered above, reply to this email and tell us. [Name], [company]
Template 3: cover note for the full report
Subject: Report on the [date] [feature] outage Hello [first name], Our report on the outage on [date] is [attached / linked here]. In short: [feature] was unavailable from [start] to [end] ([duration]); the cause was [confirmed cause, or "not yet confirmed"]; and we have [fixed it / put a workaround in place]. The report lists what we are changing, with an owner and a date for each item. If anything in it does not match what you saw, please reply and we will correct it. [Name], [company]
Sentences that cause trouble later
| Avoid | Why | Say instead |
|---|---|---|
| "This will never happen again." | You cannot promise it. The first repeat makes the email look dishonest. | "We have added [check] to catch this earlier." |
| "A small number of customers were affected." | The customer who is reading it was one of them and has no way to check the number. | The count or share, if you know it. If you do not: "some customers, including you". |
| "Human error." | It blames a person and explains nothing. It also tends to invite questions about who. | Describe the gap: "a change went out without a check that would have caught it". |
| "We will credit your account." | A promise that someone with authority has to agree first. | Say nothing about credits until it is decided, then state the exact amount. |
| "Due to unforeseen circumstances." | Customers read it as hiding something. | What actually happened, in one plain sentence. |
Before you send
- Every time has a zone next to it, and it is the same zone throughout.
- The start time is when the problem began, not when you noticed it.
- Nothing in it is a guess presented as a fact. Mark unknowns as unknown.
- No personal names of staff, and no customer data from the incident.
- One clear next step and a date for the next message.
Working out the times and checking your draft
The free timeline calculator and report checker turns a pasted timeline into time to detect, time to fix and total duration, and flags a draft that is missing a part or promises a refund or a guarantee. It runs in your browser and uploads nothing. For the full report that goes with these emails, see our guide to customer incident reports and the annotated example.
If you would like a first draft of the report, a status page post and a cover email made from your own incident notes, with every time or cause you did not give left as a marked blank, see the $9 draft service (AI-written by Claude, not legal advice).