Every delay gets discovered. The question is who discovers it first. If it’s you, you explain it and offer a choice. If it’s the customer, they find it on a tracking page that hasn’t changed in three days, and the first thing you hear is a complaint.

Why the notice matters more than the delay

David Maister’s 1985 essay on waiting set out propositions that have held up: uncertain waits feel longer than known ones, unexplained waits longer than explained ones, and anxiety makes waits seem longer Published. Shirley Taylor’s 1994 study of delayed airline passengers found delays hurt evaluations mainly through anger and uncertainty Published. A delay notice attacks exactly those: it makes the wait known, explains it, and shows someone is in control.

Order matters too. Angela Legg and Kate Sweeny found that people receiving mixed news mostly wanted the bad news first, while the people delivering it had to be nudged to give it that way; hearing it first left recipients less worried Published. The delay goes in the subject line and the first sentence.

Put the bad news in the subject line. Everything after it is the part they’ll actually read.

A caution: I haven’t found a published field experiment isolating the effect of a proactive delay email on ecommerce repurchase. The case rests on the waiting research and the studies in chapter 2. So hold back a random group, as below, and measure it yourself.

When to send

Send the notice the day the delay becomes likely, not the day it’s certain. Five triggers catch most delays:

• Not shipped by the promised ship date.
• No carrier scan within a day of the label, which usually means a missed pickup.
• No new scan for two days in transit, or a carrier exception.
• The carrier’s estimate passes the date you showed. Compare them daily.
• Out of stock after purchase: an oversell, a split, a backorder.

What it says

1. The news, first“Your order is running late.”
2. The new dateSet from your data, not a hope. If you can’t give one, say when you’ll write next.
3. The reason, in one sentence“The carrier missed its pickup on Tuesday,” not “unforeseen circumstances.”
4. The choiceWait, cancel for a full refund in one tap, or swap to an item in stock.
5. The remedy, if the grid calls for oneFrom chapter 11.

Templates are in Appendix B. This is a service message, not marketing, so it goes to every buyer. Keep promotions out of it, and send by SMS only to customers who gave you a number for order updates.

What the law requires

In the US, the FTC’s Mail, Internet, or Telephone Order Merchandise Rule sets a floor under all of this. It was last amended in 2014 Published. In summary:

• You need a reasonable basis to ship on time: within the time you state, or 30 days if you state none (50 if the order depends on a credit application). Shipping means into the carrier’s hands, not delivery.
• If you can’t, you must ask. Before the promised time passes, give a revised ship date (or say you don’t know one) and the choice to consent or cancel for a prompt refund.
• Silence counts as yes only for a first delay of 30 days or less. For a longer or indefinite delay, or a second one, you need express consent; without it, you cancel and refund.
• A prompt refund means within seven working days, card payments included. One billing cycle applies only where you extend the credit yourself.
• Email can carry the notice. An order-status page alone fails if the buyer doesn’t see it in time.

Violations can carry civil penalties per violation; the inflation-adjusted maximum is $53,088, as set in January 2025 Published. A delivery date shown at checkout is also a claim under the FTC Act’s ban on deception. States and other countries add their own rules. This is an operator’s summary as of September 2026, not legal advice; have counsel review your preorder, backorder and delay flows.

Published16 CFR Part 435, as amended at 79 FR 55619 (September 17, 2014); FTC, Business Guide to the FTC’s Mail, Internet, or Telephone Order Merchandise Rule. Full references in Appendix C.

Prove it works

Hold back 10% of delayed orders, at random, from the early notice for one month. They still get everything the law requires. Compare contacts per delayed order, cancellations and 90-day repeat rate. If the notice doesn’t cut contacts, rewrite it before you blame the idea.

Do this

• Build the five triggers in your shipping platform or help desk, each firing the same notice with a new date and a choice.
• Send your backorder and preorder flows to counsel with the rule’s summary above, and fix anything that ships late without asking.