As part of the Indiebound programme, Nielsen BookScan has generously agreed to supply a weekly independent Top 20 bestsellers report.

1 The 78-Storey Treehouse
by Andy Griffiths & Terry Denton
Pan Macmillan  $17.99
9781743535004
2 Harry Potter and the Cursed Child 
by J. K. Rowling, Jack Thorne & John Tiffany
Hachette $49.99
9780751565355
3 Te Arawa: A History of the Arawa People
by Don Stafford
Oratia Books $95.00
9780947506100
4 Richie McCaw 148
by Richie McCaw
Upstart Press  $69.99
9781927262788
5 Hera Lindsay Bird
by Hera Lindsay Bird
Victoria University Press $25.00
9781776560714
6 Things That Matter: Stories of Life & Death from an Intensive Care Specialist
Dr David Galler
Allen & Unwin $36.99
9781877505645
7 Witch's Cat Wanted: Apply Within
by Joy H. Davidson and Nikki Slade Robinson
Scholastic $19.00
9781775433729
8 Nutshell
by Ian McEwan
Jonathan Cape $38.00
9781911214335
9 The Kiwi Pair
by Eric Murray & Hamish Bond Penguin Books  $40.00
9780143574361
10 Cooking 4 Change: 101 Famous Kiwis Share Their Favourite Recipes
by Dick Frizzell & Christian Kasper 
llustrated Cargoship $49.99
9780473357702
11 The Black Widow
by Daniel Silva
HarperCollins  $36.99
9780732298951
12 Complacent Nation
by Gavin Ellis
Bridget Williams Books $14.99
9780947492946
13 Commonwealth
by Ann Patchett
Bloomsbury $32.99
9781408880395
14 Being Mortal: Illness, Medicine and What Matters in the End
by Atul Gawande
Profile Books  $24.99
9781846685828
15 Can You Tolerate This?
by Ashleigh Young
Victoria University Press $30.00
9781776560769
16 Salt River Songs
by Sam Hunt
Potton & Burton $24.99
9780947503031
17 The World's Worst Children
David Walliams
HarperCollins $24.99
9780008197049
18 Barkskins
Annie Proulx
Fourth Estate  $36.99
9780008191764
19 Les Parisiennes: How the Women of Paris Lived, Loved and Died in the 1940s
Anne Sebba
Weidenfeld & Nicolson $39.99
9781474601733
20 All Day at the Movies
Fiona Kidman
Vintage  $38.00
9781775538905