How to Tell a Client About a Project Delay by Email

Tell a client about a delay when you have enough information to explain the risk, not only when you have a complete solution. Waiting can leave them making plans around a date you no longer expect to meet.

Say which part of the work is affected and distinguish a confirmed new date from an estimate. Then explain what the client needs to decide, if anything.

When you can give a revised delivery date

Subject: Revised delivery date for the brochure proof

Hello Amira,

We need to move delivery of the brochure proof from Thursday to Monday, 12 October. The revised product section requires another layout review, and we won’t complete that check by Thursday.

I’m sorry for the change. We can still send the approved cover and opening pages on Thursday, while the complete proof will follow Monday by noon.

Does that leave enough time for your print review? If not, I’d like to discuss which pages you need first.

Kind regards, Alex

The message identifies the impact without hiding it behind “a small adjustment.” It also gives the client a chance to explain a dependency you may not know about.

When the new date is uncertain

Subject: Update on the dashboard delivery schedule

Hi Morgan,

The final access approval is still pending, so Friday’s dashboard handover is at risk. I’ve asked the review team to confirm their timing.

The dashboard itself is ready. Once access is approved, we need one working day to complete the checks. I’ll update you by Wednesday afternoon with either a confirmed date or the remaining blocker.

Best, Lee

Commit to the update you control. Don’t keep moving an unsupported delivery date every day.

Explain the cause without assigning blame

A client needs enough context to understand the schedule, but they rarely need a detailed account of internal disagreements. If your team missed something, acknowledge it. If an external dependency is involved, explain its effect factually.

Avoid promising that the delay will have no other consequences until you’ve checked the affected work. A shifted review can change printing, training, or another team’s availability.

After agreeing on the new plan, update the shared schedule and confirm the next milestone. Use a project status update to keep subsequent progress visible, and an apology email when you need to address a mistake directly.