Flying Thomson out of LGW last year, we checked in on-line the day before the flight and dropped our bags at check in later that day before heading for overnight accommodation. Only two of us checked the bags for the whole party, although I recall we needed to present passports and printed check-in papers for everyone travelling. We still needed to return to check-in next morning to exchange our printed check-in documents for proper boarding cards, for which we were all present.