DRAFT WIKI: I've started this on May 27, 2018 as a first pass, but need to pull more info from the rest of the thread. Feel free to add!

What flights are eligible to be upgraded?
As relevant to this thread, original booking must be:
- DL ticketed (006 stock)
- DL marketed (DL flight #)
- VS operated

NOTE ON MIXED CABIN BOOKINGS: If you are booked in coach for a domestic portion on Delta and then connecting to a VS Premium Economy segment, and trying to upgrade only the VS PE segment with DL miles, the upgrade request may be rejected by Virgin when the DL agent attempt to process it. Ask to be transferred to the international reissue desk. Explain that they will need to remove the domestic coach portion of your flight, then process the upgrade, and then reattach the domestic Y portion. VS will accept the upgrade only when the coach segment has been removed, and this all needs to be done manually by Delta.

How do I know mileage upgrade space is available?
You can either call Delta and ask the agent to check or check online. If you are going to call, see note below about how to explain this to the phone agent. Or, follow instructions in the next section to check inventory online.

X
Checking online In advance:
- Upgrades on VS pull from the same inventory as award bookings. Upgrading to Upper Class requires G class inventory, upgrading to Premium Economy requires P class inventory. Note these are Virgin fare classes that will not display on delta.com. Delta's G and P fare classes are different and should not be considered for this purpose. Only a subset of G class inventory (and presumably also of P class inventory) is available for upgrades, so merely finding G availability via the Delta or Virgin websites, or via ExpertFlyer or other sources, does not necessarily mean an upgrade will be available. Unfortunately there is no public data source that can be used to double-check what Delta agents tell you about availability.
.

• Waitlisting is not available for mileage upgrades on Virgin Atlantic or any other partner flights.

.
-
-
-

At the Airport Day of Depature:

• VS regularly offers DOD upgrades at the airport.
• Upgrades are available for cash (generally not the best value at ~$800 one way) or VS miles (same # miles as advance upgrades).
• DOD upgrades using miles can only be done with VS miles, not Delta Sky Miles.
• VS miles can be transferred from Amex MR. Transfer is usually instantaneous if you have linked your MR/VS accounts in advance, but as always Amex does not guarantee this so there is some risk involved in relying on the transfer while at the airport.

How do I request the upgrade?

• You'll need to call Delta. Be prepared to spend some time and persistence, and HUCA if necessary. Know that agents are likely to be confused about this, so be patient and call when you have time for them to research this and possibly speak with a supervisor.
  • Consider saying something along these lines to the phone agent to help clue them in that this may be something they need to look up or get help with: "I am calling to upgrade, using Sky Miles, my Virgin Atlantic flight that I booked through Delta. I understand that this is a newer benefit that is now available through the Delta/Virgin Atlantic join-venture. I know from previously calling that this is not something all agents do regularly, so thanks so much for helping me figure this out."
  • Remind the agent to check the VS flight # (not DL #) for upgrade space. Many agents may tell you you are already in a premium cabin if you're booked in VS PE, without realizing that DL's G class is not the same as VS's G class. Some may also insist that it is not possible to upgrade a VS flight with Sky Miles (it was not possible before July 2017). Be polite, but ask for a supervisor.
  • Agents seem to find the correct instructions about all this when they look up the DL/VS joint venture notes in whatever system they use.
• Waitlisting is not available for mileage upgrades on Virgin Atlantic or any other partner flights.

What should I see if/when my upgrade is correctly processed?

• Your upgraded flight will now be a VS-marketed flight #.
• You will be rebooked into the appropriate VS fare class.

Need more information on reticketing, seat selection, etc.

How much do upgrades cost?
Reports of upgrade costs are as follows (current as of May 2018):
- US<>UK, PE>UC = 25k RDM each way
- US<>UK, Y>UC = ???? each way
- US<>UK, Y>PE = ???? each way
When going from Y to PE/UC, you may need to pay the UK luxury tax (in USD or GBP) for flights exiting the UK.
When going from PE to UC, the luxury tax should not apply as it has already been charged on the PE fare.



A note about earning miles
Your upgraded ticket should still earn DL RDMs/MQMs/MQDs based on the originally purchased fare. However, the systems regularly get confused because the rebooked ticket will be identified as VS award inventory, ineligible for mileage earnings.
Keep your original (non-upgraded) receipt and monitor your miles earnings carefully. Calls or written requests via DL.com comments/complaints will result in proper mileage earnings being applied, but you may need to be persistent.
Need information about crediting flights to VS or other programs.