Adaptimmune Annual report pursuant to Section 13 and 15(d)

Share-based compensation - Option Plans (Details)

Share-based compensation - Option Plans (Details)														12 Months Ended
Share-based compensation - Option Plans (Details)	Nov. 01, 2023	Jul. 03, 2023	Jul. 01, 2022	Jul. 01, 2021	Jul. 01, 2020	Jul. 02, 2019	Jul. 05, 2018	Jun. 22, 2018	Jul. 03, 2017	Nov. 28, 2016	Aug. 11, 2016	Jun. 23, 2016	Mar. 16, 2015 GBP (£) item	Dec. 31, 2023 shares
Share based compensation
Contractual term (in years)														10 years
Number of option schemes \| item													3
RSU
Share based compensation
Exercise price \| shares														0.001
Vesting percentage (as a percent)														25.00%
Vesting period (in years)														4 years
Contractual term (in years)													10 years
Scheme limit, grants as a percentage of fully diluted share capital of the Company immediately following the IPO (as a percent)													8.00%
Scheme limit, automatic increase percentage (as a percent)													4.00%
Options granted in January 2016 and March 2015
Share based compensation
Maximum value of option grants per participant \| £													£ 60,000
Options granted in December 31, 2023 \| First anniversary
Share based compensation
Vesting percentage (as a percent)														25.00%
Options granted in December 31, 2023 \| Monthly installments over the following three years
Share based compensation
Vesting percentage (as a percent)														75.00%
Vesting period (in years)														3 years
Non-executive director \| Options granted on June 23, 2016 \| First anniversary
Share based compensation
Vesting percentage (as a percent)												25.00%
Vesting period (in years)												1 year
Non-executive director \| Options granted on June 23, 2016 \| Monthly installments over the following two years
Share based compensation
Vesting percentage (as a percent)												75.00%
Vesting period (in years)												2 years
Non-executive director \| Options granted on August 11, 2016 \| First anniversary
Share based compensation
Vesting percentage (as a percent)											100.00%
Vesting period (in years)											1 year
Non-executive director \| Options granted on November 28, 2016 \| First anniversary
Share based compensation
Vesting percentage (as a percent)										25.00%
Vesting period (in years)										1 year
Non-executive director \| Options granted on November 28, 2016 \| Monthly installments over the following two years
Share based compensation
Vesting percentage (as a percent)										75.00%
Vesting period (in years)										2 years
Non-executive director \| Options granted on July 3, 2017 \| First anniversary
Share based compensation
Vesting percentage (as a percent)									100.00%
Vesting period (in years)									1 year
Non-executive director \| Options granted on June 22, 2018 \| First anniversary
Share based compensation
Vesting percentage (as a percent)								100.00%
Vesting period (in years)								1 year
Non-executive director \| Options granted in July 5, 2018 \| First anniversary
Share based compensation
Vesting percentage (as a percent)							25.00%
Vesting period (in years)							1 year
Non-executive director \| Options granted in July 5, 2018 \| Monthly installments over the following two years
Share based compensation
Vesting percentage (as a percent)							75.00%
Vesting period (in years)							2 years
Non-executive director \| Options granted in July 2, 2019 \| First anniversary
Share based compensation
Vesting percentage (as a percent)						100.00%
Vesting period (in years)						1 year
Non-executive director \| Options granted in July 1, 2020 \| First anniversary
Share based compensation
Vesting percentage (as a percent)					100.00%
Vesting period (in years)					1 year
Non-executive director \| Options granted in July 1, 2021 \| First anniversary
Share based compensation
Vesting percentage (as a percent)				100.00%
Vesting period (in years)				1 year
Non-executive director \| Options granted in July 1, 2022 \| First anniversary
Share based compensation
Vesting percentage (as a percent)			100.00%
Vesting period (in years)			1 year
Non-executive director \| Options granted in July 3, 2023 \| First anniversary
Share based compensation
Vesting percentage (as a percent)		100.00%
Vesting period (in years)		1 year
Non-executive director \| Options granted in November 1, 2023 \| First anniversary
Share based compensation
Vesting percentage (as a percent)	25.00%
Vesting period (in years)	1 year