Contest sponsors want one file in one format, sent before a deadline. Getting that right takes about five minutes and is where a surprising number of entries fall over.
Cabrillo
Cabrillo is the plain-text format nearly every contest uses. Its header declares who you are and what you entered; each line after that is one contact.
START-OF-LOG: 3.0
CONTEST: ARRL-DX-SSB
CALLSIGN: KX4XYZ
CATEGORY-OPERATOR: SINGLE-OP
CATEGORY-POWER: LOW
CATEGORY-BAND: ALL
CLAIMED-SCORE: 12480
NAME: Sam Example
QSO: 14200 PH 2026-02-21 1834 KX4XYZ 59 TN K1ABC 59 KW
END-OF-LOG:Your logging software writes this for you — in N1MM+ it is File → Export → Cabrillo, and it will prompt for the category fields. The three things worth checking by hand:
- CONTEST must be the exact identifier the sponsor lists, or the robot cannot classify your entry.
- CATEGORY- lines must match what you actually did. Claiming Low Power while running an amplifier
- Times are UTC and dates are
YYYY-MM-DD.
is the one mistake that gets an entry moved to Checklog.
Some sponsors accept ADIF instead, and a few smaller contests still take a plain summary sheet. State QSO parties often have their own web form.
Sending it
Most contests use a web upload with a scoring robot — you paste or upload the file and get an immediate report of what it parsed. A few still take email to a submission address, in which case attach the file and put nothing clever in the subject line.
Deadlines are firm and short: commonly 5 to 30 days after the contest ends. Check the rules; missing it usually means your log is accepted only as a checklog.
What happens next
- The robot parses and acknowledges your file. Read the confirmation email — it tells you the
- Log checking cross-references every contact against the other station's log. Contacts the other
- Results appear weeks or months later, listing every entrant with a claimed and a final score,
category it filed you under and the score it computed, which is a useful sanity check.
station did not log, or logged with a different callsign or exchange, are removed and usually carry a penalty. This is why you should log what you heard, not what you assumed.
and often the error rate.
Entering as a checklog
If you made a handful of contacts and do not care about a score, submit anyway with the category the rules give for a checklog. Your log still helps verify everyone you worked, which is a real contribution and costs you nothing.
Club and multi-operator entries
Contests score clubs as well as individuals: enter the club's name in the CLUB: field exactly as the sponsor spells it, and every member's entry contributes. Multi-operator entries need every operator's callsign in the header, and the category rules about who may transmit when are stricter than most first-timers expect — read them before Field Day weekend, not during it.