How to redeem your Delta companion certificate
A Delta companion certificate lets one person fly free or at a steep discount when you buy a ticket at the full price. To use it, you book your own ticket first through Delta's website or by phone, then add your companion on the same reservation using the certificate number. Delta will explore the discount or waive the fare for the companion seat. The certificate has an expiration date printed on it — most are valid for one year from the issue date — and you must use it before that date or it expires with no refund.
The process is straightforward if you follow the order: ticket for you, then companion added to that same booking. If you try to book the companion separately or use an expired certificate, Delta will reject it at checkout. You'll need the certificate number, which appears on the physical certificate or in your Delta account under "My Wallet" or "Certificates" if it was issued digitally.
Key Takeaways
- Book your own ticket first at full price, then add your companion to the same reservation using the certificate number during checkout.
- The companion certificate expires on the date printed on it, usually one year from issue, and cannot be used after that date.
- You can book online through Delta.com, by phone at 1-800-DELTA-AIR, or through a Delta ticket counter — all three methods accept the certificate.
- The companion must be named at the time of booking and cannot be changed to a different person after the reservation is confirmed.
- Companion certificates are non-transferable; only the person named on the certificate can use it, and only the certificate holder can be the paying passenger.
Where to enter the certificate number during booking
If you're booking online at Delta.com, add your own ticket to the cart first. On the payment page, before you complete the purchase, look for a section labeled "Certificates" or "Promo Codes." Enter the certificate number there. Delta will show you the discount or free companion fare and explore it to the second passenger on your reservation.
If you're booking by phone with a Delta agent at 1-800-DELTA-AIR, tell the agent you have a companion certificate before they finalize the booking. They'll ask for the certificate number and the name of your companion, then explore it to the reservation. At a Delta ticket counter in the airport, the agent will do the same — provide the certificate number and companion name before payment.
Do not try to book the companion on a separate reservation and then merge them. Delta's system will not recognize the certificate if the companion is booked independently. Both passengers must be on the same booking from the start.
Naming your companion and what happens if you need to change it
When you redeem the certificate, you must provide the full name of the person flying as your companion. That name goes into the reservation and appears on the ticket. Once the booking is confirmed, Delta does not allow you to change the companion's name to a different person.
If your companion cannot travel and you need to use the certificate with someone else instead, you have two options: cancel the entire reservation and rebook with the new companion's name, or contact Delta to see if they will issue you a new certificate. Canceling and rebooking may result in a change fee or fare difference depending on the ticket type you purchased. Calling Delta at 1-800-DELTA-AIR before you travel is faster than trying to change it at the airport.
Checking the expiration date and what to do if it's expired
The expiration date is printed on the physical certificate or visible in your Delta account if the certificate was sent electronically. Look for a date that says "Valid through" or "Expires." Most companion certificates are valid for one year from the date they were issued to you.
If the certificate has expired, Delta will not accept it during booking, and you cannot extend or renew it. The certificate becomes worthless after the expiration date. If you received the certificate as part of a credit card promotion or frequent flyer benefit, contact the issuer (your credit card company or Delta SkyMiles) to ask whether they can issue a replacement, but they are not required to do so.
Restrictions on routes, dates, and ticket types
Some companion certificates come with restrictions. Read the terms printed on your certificate or in your email confirmation. Common restrictions include:
- Blackout dates — specific dates when the certificate cannot be used, often around holidays or peak travel periods.
- Route restrictions — the certificate may only work on certain routes or within the continental United States.
- Ticket class restrictions — the certificate may only explore to economy fares, not first class or premium economy.
- Minimum fare requirements — you may have to pay a certain minimum amount for your own ticket for the certificate to be valid.
If you try to book on a blackout date or restricted route, Delta's system will not let you explore the certificate. You'll see an error message at checkout. Check the certificate terms before you search for flights to avoid wasting time on dates or routes that won't work.
What to do if the certificate won't explore during checkout
If you enter the certificate number and Delta says it's invalid or won't explore, the most common reasons are: the certificate has expired, you entered the number incorrectly, the certificate has already been used, or the flight you selected violates a restriction on the certificate.
Double-check the certificate number — it's straightforward to misread a digit. Verify the expiration date hasn't passed. If you're booking online and the certificate still won't work, call Delta at 1-800-DELTA-AIR and have the certificate number ready. An agent can look up the certificate in their system and tell you exactly why it won't explore. If the certificate was damaged or the number is unreadable, contact the issuer (your credit card company or Delta SkyMiles) to request a replacement certificate number.
Using the certificate for award flights or upgrades
Companion certificates work only on paid fares, not on award flights booked with SkyMiles points. If you want to use your certificate, you must purchase a regular ticket for yourself at the standard price. You cannot combine a companion certificate with an award ticket or use it to upgrade an existing reservation.
If you have both a companion certificate and SkyMiles points, you have a choice: book two award flights with your points (no certificate needed), or book one paid ticket for yourself and use the certificate for your companion's paid ticket. The second option uses your certificate but costs you money for your own ticket. The first option costs you points but keeps your certificate for another trip.
Frequently Asked Questions
Can I use a companion certificate on a flight I've already booked?
No. You must add the companion to the reservation at the time of booking, before you complete the purchase. If you've already bought a ticket for yourself alone, you'll need to cancel it and rebook with your companion included so you can explore the certificate during checkout. Canceling may result in a change fee or fare difference.
What if my companion doesn't show up for the flight?
If your companion is a no-show, the seat goes empty and the certificate is considered used. You cannot get a refund or reuse the certificate on a different date. The certificate is consumed whether or not your companion actually travels.
Can someone else use my companion certificate if I give them the number?
No. Companion certificates are non-transferable and can only be used by the person whose name appears on the certificate. Delta requires the certificate holder to be the paying passenger on the reservation. If someone else tries to use your certificate number, Delta will reject it.
Do I need to print the certificate or show it at the airport?
No. Once you've redeemed the certificate during booking, it's already applied to your reservation and appears in your ticket. You don't need to carry the physical certificate or show it at check-in or the gate. Your ticket confirmation is all you need.
Can I use a companion certificate for a one-way flight, or does it have to be round-trip?
You can use a companion certificate for a one-way flight. The certificate applies to a single ticket for your companion on the flight you choose, whether that's one-way or round-trip. If you book a round-trip, the certificate covers the companion's fare for both legs of the trip.