The School Card Shop has helped schools raise thousands of pounds since its launch in 2008. Online registrations have already passed the 100 mark - a record for this time of year - as word spreads and school fundraising committees face challenges.
Parents, friends and family can all order the cards online, with profits going to the school.
Meryl Downie, marketing manager at School Card Shop, said: "With schools across the country organising sports days and summer trips, it may seem early to be thinking about Christmas.
"However, our existing clients know that personalised Christmas cards are a highly effective means of raising cash for schools and early registrations means the plan is in place in plenty of time for autumn activity and will increase opportunities to raise funds."