The Confirmation created when you and your QSO partner first submit matching QSO descriptions can subsequently be updated or refined with additional information.
Updating an Existing Confirmation
Submitting a QSO to LoTW whose callsign, station callsign, date, time, band, RX band, and mode exactly match those of a QSO that has already been confirmed via LoTW will update the Confirmation's US State, grid squares, propagation mode, and satellite name unless doing so would modify an already-granted award credit. The confirmation's CQ zone, ITU zone, IOTA group, Australian State or Territory, Chinese District, Russian Oblast, or US County will also be updated.
Suppose that you previously submitted a QSO with AD1C on 6m, but failed to specify your grid square in the Station Location used to submit this QSO. When AD1C submitted this QSO with a matching date, time, and band, a Confirmation was created for each of you, but AD1C's Confirmation lacks the grid square needed for the VUCC award he's pursuing. If you add your grid square to your Station Location and use this updated Station Location to resubmit your QSO to LoTW, AD1C's Confirmation will be updated to reflect the grid square you've now specified.
Further suppose that AD1C includes this Confirmation in a VUCC application, which is approved. If you were to then change the grid square in your Station Location and use that Station Location to resubmit the QSO, AD1C's confirmation would not be updated with the new grid square, because award credit was already granted to the grid square you previously specified.
Updating a Confirmation to Obtain an Exact Mode Match
For DXCC awards, the mode information that you and your QSO partner submit to LoTW need not match exactly. Suppose, for example, that you work W9OL in RTTY. Further suppose that W9OL uploads the QSO with a mode of RTTY, but you upload it with a mode of DATA; the resulting Confirmations you each receive will be valid for DXCC Digital awards.
However, a RTTY-DATA Confirmation cannot be submitted for a WAS RTTY award - because single-mode WAS endorsements require an exact mode match.
A Confirmation that lacks an exact mode match can be updated by resubmitting the QSO with
- a mode that exactly matches the mode submitted by your QSO partner
- a callsign, station callsign, band, and RX band that exactly match those submitted by your QSO partner
- a date and time that is within 30 minutes of the date and time submitted by your QSO partner
Note that this resubmission inserts a new QSO into LoTW, and uses the new QSO to generate an updated Confirmation. The original QSO remains present, but is no longer confirmed.
If your QSO partner submitted multiple QSOs with times within a 30 minute interval, and if you resubmit your QSO with a mode that exactly matches the modes of several of those QSOs, LoTW will confirm the QSO submitted by your QSO partner whose time is closest to the time specified in your QSO.
In summary, until a Confirmation has been granted award credit, LoTW will when inserting new QSOs seek the best possible match with what your QSO partners have submitted, where best means an exact mode match and the smallest difference in QSO start times.