| Document and Entity Information | Apr. 05, 2024 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Apr. 05, 2024 |
| Entity File Number | 001-39992 |
| Entity Registrant Name | Immunocore Holdings plc |
| Entity Central Index Key | 0001671927 |
| Entity Incorporation, State or Country Code | X0 |
| Entity Tax Identification Number | 00-0000000 |
| Entity Address, Address Line One | 92 Park Drive |
| Entity Address, Address Line Two | Milton Park |
| Entity Address, Address Line Three | Abingdon |
| Entity Address, City or Town | Oxfordshire |
| Entity Address, Country | GB |
| Entity Address, Postal Zip Code | OX14 4RY |
| City Area Code | 44 |
| Local Phone Number | 1235 438600 |
| Title of 12(b) Security | American Depositary Shares, each representing one ordinary share, nominal value £0.002 per share |
| Trading Symbol | IMCR |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
