  CPT invariance is one of the most fundamental symmetries in nature and it
plays a major role in the formulation of Quantum Field Theory. Although no
definitive signal of CPT violation has been observed so far, there are many
reasons to carefully investigate various low-energy phenomena that can provide
better probes to test CPT symmetry. In this context, neutrino experiments are
expected to provide more stringent bounds on CPT invariance violation when
compared to the existing bounds from the Kaon system. In this work, we
investigate the sensitivity of the upcoming long-baseline experiments: Hyper
Kamiokande (T2HK, T2HKK), ESSnuSB and DUNE to constrain the CPT violating
parameters $\Delta(\delta_{CP})$, $\Delta(m^2_{31})$ and $\Delta(\sin^2
\theta_{23})$, which characterize the difference between neutrino and
antineutrino oscillation parameters. Further, we analyse neutrino and
antineutrino data independently and constrain the oscillation parameters
governing them by considering the combination of these experiments (DUNE+T2HKK
and DUNE+ESSnuSB). In addition, assuming CPT symmetry is violated in nature, we
study the individual ability of the aforementioned experiments to establish CPT
violation. We found that the experiments Hyper-K (T2HK, T2HKK) and ESSnuSB,
along with DUNE, will be able to establish CPT violation in their proposed
run-times.
