The new off payroll working rules from April 2020 will shift the IR35 responsibility for medium to large companies in the private sector, from the PSC, on to the hiring party. This will bring medium and large companies in the private sector into a similar regime to with the public sector has worked under since April 2017
There is currently a lot of nervousness around how these changes may affect contractors, but If IR35 does not currently apply, then by continuing to comply with the existing IR35 rules, you should not be affected by these changes, but some hirers may take a blanket approach and classify consultants as inside of IR35 to avoid ambiguity or risk of potential penalties.
The only way to obtain any potential clarity around this before April 2020 would be to ask your client to clarify what your status is, and if you have a disagreement maybe a negotiation is possible before April 2020.
If the client has deemed the engagement to be inside of IR35, then you do have the right to appeal against the determination and the engager has to respond within 45 days stating the reasons why they believe IR35 applies.
IR35 applies on a contract by contract basis, so if IR35 applies to your contract, the next on is taken on its own merits.