When you need to tell someone you will not arrive on time, the words you choose can change how your message is received. In formal settings, such as a work email to a manager or a message to a client, you need to show respect, give a clear reason, and offer a solution. In casual settings, like texting a friend or a family member, you can be direct and simple. This guide gives you the exact phrases to use in both situations, with examples and common mistakes to avoid.
Quick Answer: Which Phrase Should You Use?
If you are writing to a boss, client, or professor, use a formal phrase like “I apologize for the delay; I will be arriving at 10:15.” If you are texting a friend or colleague you know well, use a casual phrase like “Sorry, running late. Be there in 10.” The key difference is that formal phrases include an apology, a specific time, and often a brief reason, while casual phrases are short and assume the listener understands.
Formal Ways to Say ‘I will be late’
Formal language is necessary in professional emails, official messages, and any situation where you need to show respect. These phrases are polite, clear, and often include a plan for how you will handle the delay.
Professional Email Alternatives
When you send an email to a manager, client, or team lead, use these phrases. They show you are responsible and considerate of their time.
- “I apologize for the inconvenience, but I will be arriving approximately 15 minutes late.” – Use this when you know the exact delay. It is polite and direct.
- “Please accept my apologies for the delay. I will be there by 10:30.” – Good for when you have a specific new arrival time.
- “Due to an unexpected situation, I will be arriving later than planned. I will update you as soon as I have a clearer estimate.” – Use this when you do not know exactly how late you will be.
- “I regret to inform you that I will be delayed. I am doing my best to arrive as soon as possible.” – A very formal option for important meetings.
Workplace Speaking Phrases
If you need to tell a colleague or supervisor in person or over the phone, these phrases work well.
- “I wanted to let you know that I will be a bit late for the meeting. I apologize for any disruption.”
- “I am running behind schedule. I will be there shortly.”
- “Please excuse my lateness. I will join the meeting as soon as I arrive.”
Casual Ways to Say ‘I will be late’
Casual language is for friends, family, and close coworkers. These phrases are short, friendly, and do not require a detailed explanation.
Polite Everyday Phrases
Even in casual settings, you can be polite without being formal.
- “Sorry, I’m running late. I’ll be there in 10.” – Simple and clear.
- “Hey, I’m going to be a little late. See you soon.” – Friendly and direct.
- “My bad, I’m stuck in traffic. ETA 15 minutes.” – Very casual, best for close friends.
- “I’m on my way, but I’m behind schedule. Don’t wait for me.” – Considerate even in a casual tone.
Comparison Table: Formal vs Casual
| Situation | Formal Phrase | Casual Phrase |
|---|---|---|
| Email to boss | “I apologize for the delay; I will arrive at 10:15.” | “Sorry, running late. See you at 10:15.” |
| Text to friend | Not appropriate | “Running late! Be there soon.” |
| Phone call to client | “I regret to inform you that I will be delayed.” | Not appropriate |
| Message to coworker | “I will be approximately 10 minutes late.” | “Gonna be 10 min late.” |
| Group chat with team | “Please accept my apologies for the delay.” | “Sorry all, running behind.” |
Natural Examples
Seeing phrases in real contexts helps you understand when to use them. Here are examples for both formal and casual situations.
Formal Example: Email to a Manager
Subject: Update on Arrival Time
Dear Ms. Chen,
I apologize for the inconvenience, but I will be arriving approximately 20 minutes late to our 9:00 AM meeting. There was an unexpected delay on the train. I will join the call as soon as I arrive. Thank you for your understanding.
Best regards,
James
Casual Example: Text to a Friend
You: Hey, sorry I’m running late. Traffic is terrible.
Friend: No worries! Take your time.
You: Thanks. ETA 10 minutes.
Formal Example: Phone Call to a Client
“Hello, this is Sarah. I wanted to let you know that I will be delayed for our appointment. I apologize for any inconvenience. I should be there within 15 minutes.”
Casual Example: Message to a Roommate
“Hey, gonna be late tonight. Don’t wait up for dinner.”
Common Mistakes
English learners often make these errors when saying they will be late. Avoid them to sound natural and polite.
Mistake 1: Being too vague in formal situations
Incorrect: “I will be late.” (No apology, no time, no reason)
Correct: “I apologize, but I will be approximately 10 minutes late due to traffic.”
Mistake 2: Using casual language with a boss or client
Incorrect: “Hey, I’m running late. See you soon.” (Too casual for a professional email)
Correct: “I wanted to inform you that I will be delayed. I will arrive as soon as possible.”
Mistake 3: Over-apologizing in casual settings
Incorrect: “I am so incredibly sorry for being late. Please forgive me.” (Too formal for a friend)
Correct: “Sorry, running late. Be there in 5.”
Mistake 4: Not giving a new time estimate
Incorrect: “I will be late.” (The listener does not know when to expect you)
Correct: “I will be late. I should be there by 10:30.”
Better Alternatives for Specific Situations
Sometimes you need a phrase that fits a particular context. Here are better alternatives for common scenarios.
When you are stuck in traffic
- Formal: “I am delayed due to heavy traffic. I will arrive as soon as possible.”
- Casual: “Stuck in traffic. ETA 15.”
When you have a family emergency
- Formal: “Due to a personal matter, I will be unable to arrive on time. I will keep you updated.”
- Casual: “Something came up at home. I’ll be late.”
When you are running late for a meeting you are leading
- Formal: “I apologize for the delay. Please begin the meeting without me, and I will join shortly.”
- Casual: “Start without me. I’ll be there in a few.”
Mini Practice Section
Test your understanding with these four questions. Choose the best phrase for each situation.
Question 1
You are emailing your manager to say you will be 15 minutes late to a team meeting. What should you write?
A. “Hey, I’m late. See you soon.”
B. “I apologize for the delay. I will be approximately 15 minutes late to the meeting.”
C. “Sorry, running behind.”
Answer: B. This is polite, specific, and appropriate for a manager.
Question 2
You are texting a close friend who is waiting for you at a café. What is the best message?
A. “I regret to inform you that I will be delayed.”
B. “Running late! Be there in 10.”
C. “Please accept my apologies for the inconvenience.”
Answer: B. This is friendly, casual, and gives a time estimate.
Question 3
You are on a phone call with a client and you are stuck in traffic. What should you say?
A. “My bad, I’m stuck in traffic.”
B. “I apologize for the delay. I am stuck in traffic and will be there within 15 minutes.”
C. “I’m late. See you later.”
Answer: B. This is professional, gives a reason, and provides a new time estimate.
Question 4
You are in a group chat with coworkers and you will be 5 minutes late to a casual lunch. What is appropriate?
A. “I apologize for the inconvenience, but I will be delayed.”
B. “Sorry all, running 5 min late. Save me a seat.”
C. “Due to unforeseen circumstances, I will be late.”
Answer: B. This is casual, friendly, and fits the informal setting.
FAQ: Saying ‘I will be late’
1. Should I always give a reason when I am late?
In formal situations, yes. Giving a brief reason (traffic, a meeting ran over) shows respect and helps the other person understand. In casual situations, a reason is optional. A simple “Sorry, running late” is often enough.
2. Is it rude to say “I will be late” without apologizing?
In formal settings, yes. Always include an apology like “I apologize” or “Sorry for the delay.” In casual settings with close friends, a direct “I’m late” can be acceptable, but adding “sorry” is always polite.
3. What if I do not know exactly how late I will be?
Be honest. Say something like, “I am delayed and I am not sure of my exact arrival time. I will update you as soon as I know more.” This is better than giving a wrong estimate.
4. Can I use “I will be late” in a text message?
Yes, but it sounds a bit stiff. Native speakers usually say “I’m running late” or “I’m going to be late.” “I will be late” is more common in written formal communication like emails.
For more help with polite everyday language, visit our Polite Everyday Phrases section. If you need professional email alternatives, check out Professional Email Alternatives. For workplace speaking, see Workplace Speaking Phrases. To learn more about our approach, read our Editorial Policy or visit our About Us page.