v3.25.2
Intangible assets
 6 Months Ended
Jun. 30, 2025
Goodwill and Intangible Assets Disclosure [Abstract]  
Intangible assets Intangible assets
The carrying amount of Intangible Assets as of June 30, 2025 and December 31, 2024 is as follows:

June 30,
2025		December 31,
2024
(in thousands)
Cost
Customer relationships$4,134,482 $4,129,501 
Order backlog545,993 543,933 
Trade names & brands204,717 204,588 
Patient database170,563 170,324 
Technology assets151,718 150,658 
Total cost5,207,473 5,199,004 
Accumulated amortization(1,764,377)(1,639,212)
 Net book value$3,443,096 $3,559,792 

In the three months ended June 30, 2025, the amortization expense recognized by the Company was $59.1 million (three months ended June 30, 2024: $116.5 million).

In the six months ended June 30, 2025, the amortization expense recognized by the Company was $118.0 million (six months ended June 30, 2024: $233.0 million and year ended December 31, 2024: $350.3 million). The decrease in amortization is due to the order backlog and trade name intangible assets recognized in connection with the merger of Indigo Merger Sub, Inc., a Delaware corporation and subsidiary of ICON, with and into PRA Health Sciences, Inc., the parent of PRA Health Sciences on July 1, 2021 ("PRA Merger") amounting to $500.0 million and $202.0 million respectively as of the date of acquisition, becoming fully amortized on July 1, 2024.

There were no additions to intangible assets during the six months ended June 30, 2025.