The Complete Borrowers

From Author Wars - https://authorwars.com/publications/the-complete-borrowers-460585.html

Overview:

Title: The Complete Borrowers
Author: Mary Norton
Year: 2007
ISBN-10: 9780141322704
Publisher: Puffin
Pages: 711
Binding: Trade Paperback
Type: Omnibus
Title Reference: The Borrowers
Notes:
Cover artist from Phil Baines' Puffin by Design.

As of 2017-11-11, Amazon UK reports publ date 2007-09-27; provides image of variant cover with footer "All SIX Borrowers adventures in one". (Amazon US reports the same publication date and shows the cover of another book.)