The last Potter book won't be out for months yet, but postal workers are already planning how they'll deliver it to thousands of fans.
JK Rowling revealed last week that the seventh book will be called Harry Potter and the Deathly Hallows, but she wouldn't give a release date for it.
Royal Mail delivered a whopping 500,000 copies of Potter six to UK homes.
Apart from Christmas, the release of a Potter book is one of the busiest times of the year for the post office.
Some online shops have already taken hundreds of orders for Potter seven, even though the book's not out yet. There's rumours that the Deathly Hallows will come
out in the summer, but no-one really knows for sure.
Bosses at the post office said they'll be having meetings with people from online shops to help plan how many books they might have to deliver and how they'll do it.
Fascinating fact! One in every 18 households in the town of Royston in Hertfordshire had a copy of Harry Potter and the Half-Blood Prince delivered to their doors in 2005.