Answer
What should you do when you cannot meet a deadline?
Tell them as soon as you know, with a new date you are confident of and what you are doing about it.
Tell them the moment you know, not the day it was due. Give a new date you are confident of, say what changed and what you are doing, and never let a second date slip without warning.
The instinct is to wait, in case it can still be recovered. That instinct is why most deadline conversations happen too late to be useful. From the customer's side there is a large difference between being told a week ahead — when they can still rearrange, warn their own people, adjust their plans — and being told on the day, when they have already made commitments based on yours.
So the rule is to communicate at the moment the belief changes rather than at the moment the deadline arrives. That is uncomfortable because the recovery is still theoretically possible, and it is the point at which the information is worth most. A message saying you now expect this to take until Thursday, sent when you first believe it, is a professional communication. The same information on the original due date is an apology.
The new date has to be one you are confident of, which usually means later than the optimistic version. A second missed date does disproportionate damage, because it removes the customer's ability to believe anything you say about timing, and after that every subsequent commitment is discounted. Giving a date you would be comfortable beating is not sandbagging in this situation; it is the only way to restore the credibility the first miss cost.
What to include beyond the date matters less than people think, with one exception. A short statement of what changed is useful and a long explanation is not — it reads as building a case, and the customer is not adjudicating. What genuinely helps is saying what you are doing about it, because that is the part that tells them whether this is being managed or merely reported.
Where the delay has consequences for the customer, offering something is proportionate and it should be specific rather than a general apology. Prioritising a part of the work they need first, absorbing a cost the delay creates for them, or adjusting the price where the delay materially reduced the value. Small and specific beats large and vague, and it converts an incident into evidence that the business handles problems.
Afterwards, the useful question is why the original date was given. Deadlines are missed for causes that repeat — estimates based on the good case, dependencies on other parties, capacity committed twice, customer-side inputs assumed to arrive on time. A pattern of missed dates is a estimating problem rather than a series of unlucky events, and it is fixable by quoting against the realistic case rather than the achievable one.
Customers forgive delays and remember being told on the day it was due that it would not be ready.
Answer Production Engine, Context Theory
Related questions
What if the delay is the customer's fault?
Say so once, factually and without emphasis, at the time it happens rather than at the end. A note when an input is late saying this will move the completion date is a normal project communication and it is accepted. The same point made afterwards, as an explanation for missing the date, reads as blame regardless of accuracy and is remembered that way.
Should we offer a discount for being late?
Only where the delay caused actual cost or loss, and preferably as something specific rather than a general reduction. A discount offered reflexively teaches the customer that lateness is a negotiating opportunity and sets an expectation for the next occurrence. Addressing what the delay actually cost them is both more proportionate and better received.
METHOD
Every figure below carries its source and the date it was verified. Nothing on this page is asserted.
The numbers on this page.
| What | Value | Specific to |
|---|---|---|
| Firms that never responded to a web enquiry at all | 23% | Category-wide |
| Average B2B first-response time | 42 hrs | Category-wide |
| Odds of making contact — replying within 5 minutes vs within 30 | 100× | Category-wide |
Oldroyd, McElheran & Elkington, "The Short Life of Online Sales Leads", Harvard Business Review (March 2011) · hours · 1.25M inbound leads across 2,241 US firms · verified
Oldroyd, J. B. — MIT / InsideSales.com Lead Response Management Study (2007) · the original five-minute finding; contact, not qualification · verified
What is specific to this page.
| Kind | Claim | Check it against |
|---|---|---|
| Workflow | Notice given a week ahead allows the customer to rearrange and warn their own people, while notice on the due date arrives after they have made commitments based on the original date, which is where the damage originates. | The business's own complaint records on delayed work, segmented by how much notice was given. |
| Buying behaviour | A second missed date removes the customer's ability to believe any subsequent timing commitment, which makes a conservatively chosen replacement date the mechanism for restoring credibility rather than sandbagging. | Customer behaviour after a second slippage, in requests for confirmation and in subsequent order timing. |
| Workflow | A long explanation reads as building a case to a customer who is not adjudicating, whereas saying what is being done about it indicates whether the situation is managed rather than merely reported. | Customer responses to short action-focused delay notices against longer explanatory ones. |
| Procurement | Repeated missed dates indicate estimating against the good case rather than a series of unlucky events, with the recurring causes being assumed dependencies, double-committed capacity and customer inputs presumed timely. | The business's own late jobs over a year, classified by cause and checked for repetition. |
Each row would be wrong on another industry's page. Where a sourced figure exists it is in the table above instead; these are the constraints that shape the work and do not happen to be numbers.
Start with the measurement.
Reading about a benchmark is not the same as knowing your own number. The audit produces yours, measured rather than estimated.
$497 · delivered in 5 business days · credited against month one