Annual and transition report of foreign private issuers pursuant to Section 13 or 15(d)

Business combination agreement - Fair value of deemed shares issued (Details)

v3.22.2.2
Business combination agreement - Fair value of deemed shares issued (Details)
1 Months Ended 12 Months Ended
Sep. 03, 2021
USD ($)
shares
Sep. 30, 2021
USD ($)
$ / shares
Sep. 30, 2022
USD ($)
item
$ / shares
shares
Sep. 30, 2021
USD ($)
$ / shares
Sep. 30, 2020
USD ($)
Sep. 02, 2021
$ / shares
Apr. 25, 2021
$ / shares
Disclosure of detailed information about business combination [line items]              
Share Exchange Ratio | item     46.06        
Price per share | $ / shares   $ 0.0001 $ 0.0001 $ 0.0001   $ 0.0001 $ 1
Profit / (loss) for the year | $   $ 651,973 $ 65,075,000 $ (271,729,000) $ (568,000)    
Business Combination Agreement              
Disclosure of detailed information about business combination [line items]              
Shares issued 90,000,000            
Arqit Limited              
Disclosure of detailed information about business combination [line items]              
Profit / (loss) for the year | $   $ 651,973          
Arqit Limited | Business Combination Agreement              
Disclosure of detailed information about business combination [line items]              
Share Exchange Ratio | item     46.06        
Exchanged for shares in the Company in reverse acquisition (in shares) 1,954,174            
Fair value of the shares issued | $ $ 223,517,945            
Number of deemed shares issued representing same percentage of equity interest acquired 485,326            
Centricus Acquisition Corp. | Business Combination Agreement              
Disclosure of detailed information about business combination [line items]              
Number of ordinary shares for each ordinary share held     1        
Number of warrants for each warrant held     1        
Centricus Acquisition Corp. | Subscription Agreements              
Disclosure of detailed information about business combination [line items]              
Shares issued     7,100,000        
Shares issued value | $     $ 71,000,000        
Price per share | $ / shares     $ 10.00