NOW THAT'S WHAT I CALL MUSIC! 40 by NOW SERIES (UK) has sold 900,000 copies in United Kingdom.
NOW THAT'S WHAT I CALL MUSIC! 40 certifications and sales
| Country / region | Sales | Certification / source | Certification date / sales as of | |
 United Kingdom |
900,000 | 3x Platinum | 4 December, 1998 |
United Kingdom Sales: 900,000
Certification / note: 3x Platinum
Certification Date / sales as of: 4 December, 1998
|
| Total sales | 900,000 | (in 1 country) |
Total
Sales: 900,000
(in 1 country)
|
Year-end chart performance for NOW THAT'S WHAT I CALL MUSIC! 40
| Chart 1998 | Rank | Sales |
| UK Albums |
24 | 560,000 |