| Season | Team | Competition | MP | G | A | Rating | ||
|---|---|---|---|---|---|---|---|---|
| 2024/2025 | Maidstone United | FA Cup | 0 | 0 | 0 | 0 | 0 | – |
| 2024/2025 | Southend United | FA Trophy | 1 | 0 | 0 | 0 | 0 | – |
| 2024/2025 | Milton Keynes Dons | League Cup | 1 | 0 | 0 | 0 | 0 | 6.3 |
| 2024/2025 | Milton Keynes Dons | EFL Trophy | 2 | 0 | 0 | 0 | 0 | 6.5 |
| 2023/2024 | Gateshead | FA Trophy | 0 | 0 | 0 | 0 | 0 | – |
| 2023/2024 | Milton Keynes Dons | League Cup | 0 | 0 | 0 | 0 | 0 | – |
| 2023/2024 | Milton Keynes Dons | EFL Trophy | 1 | 0 | 0 | 0 | 0 | 7.7 |
| 2023/2024 | Milton Keynes Dons | FA Cup | 0 | 0 | 0 | 0 | 0 | – |
| 2022/2023 | Charlton Athletic U21 | Premier League Cup | 1 | 0 | 0 | 0 | 0 | – |
| 2022/2023 | Charlton Athletic | EFL Trophy | 1 | 0 | 0 | 0 | 0 | 6.5 |
| 2022/2023 | Charlton Athletic | FA Cup | 0 | 0 | 0 | 0 | 0 | – |
| 2022/2023 | Charlton Athletic | EFL Trophy | 2 | 0 | 0 | 0 | 0 | 6.5 |
| 2022/2023 | Charlton Athletic | FA Cup | 0 | 0 | 0 | 0 | 0 | – |
| 2022/2023 | Charlton Athletic | League Cup | 0 | 0 | 0 | 0 | 0 | – |
| 2021/2022 | Charlton Athletic | EFL Trophy | 0 | 0 | 0 | 0 | 0 | 7.1 |
| 2021/2022 | Charlton Athletic | EFL Trophy | 5 | 0 | 0 | 0 | 0 | 7.1 |
| 2021/2022 | Charlton Athletic | League Cup | 0 | 0 | 0 | 0 | 0 | – |
| 2021/2022 | Charlton Athletic | FA Cup | 0 | 0 | 0 | 0 | 0 | – |
| 2020/2021 | Charlton Athletic | EFL Trophy | 0 | 0 | 0 | 0 | 0 | – |
| 2020/2021 | Charlton Athletic | League Cup | 0 | 0 | 0 | 0 | 0 | – |
| 2020/2021 | Charlton Athletic | FA Cup | 0 | 0 | 0 | 0 | 0 | – |
| 2019/2020 | Charlton Athletic | FA Cup | 0 | 0 | 0 | 0 | 0 | – |
| 2017/2018 | Stevenage U18 | FA Youth Cup | 2 | 0 | 0 | 0 | 0 | – |
| Total | 16 | 0 | 0 | 0 | 0 | – | ||
| Date | From | To | Type | |
|---|---|---|---|---|
| 01 Jun 2020 | Charlton Athletic | Billericay Town | Loan | |
| 02 Jun 2020 | Billericay Town | Charlton Athletic | Back from Loan | |
| 12 Jul 2020 | Charlton Athletic | Welling United | Loan | |
| 01 Mar 2021 | Welling United | Charlton Athletic | Back from Loan | |
| - | Charlton Athletic | Dulwich Hamlet FC | Loan | |
| - | Dulwich Hamlet FC | Charlton Athletic | Back from Loan | |
| - | Charlton Athletic | Bromley | Loan | |
| - | Bromley | Charlton Athletic | Back from Loan | |
| 07 Jan 2023 | Charlton Athletic | Milton Keynes Dons | Free Transfer | |
| - | Milton Keynes Dons | Gateshead | Loan | |
| 07 Jan 2024 | Gateshead | Milton Keynes Dons | Back from Loan | |
| - | Milton Keynes Dons | Wealdstone | Loan | |
| 01 Jan 2025 | Wealdstone | Milton Keynes Dons | Back from Loan | |
| - | Milton Keynes Dons | Southend United | Loan | |
| - | Southend United | Milton Keynes Dons | Back from Loan | |
| 06 Jan 2025 | Milton Keynes Dons | Southend United | Loan | |
| - | Southend United | Maidstone United | Free Transfer |
N. Harness career history shows progression across clubs and competitions, including club timeline, national team appearances and overall career totals.