So case closed as far as I'm concerned, have accepted the NIP online.
Maybe, maybe not.
You cannot "accept" or decline a NIP.
Some forces allow the driver to admit to being the driver online - either by scanning the signed s. 172 response, or by completing a section that is clearly intended to be taken as a signature. Either way, the s. 172 requirement will require a "signature" of some description.
Most forces don't. Some allow the recipient of a NIP who was not the driver to nominate the driver online, as after 30+ years they have finally grasped that a signature is only relevant when the recipient of the notice admits to being the driver. We have seen cases where the driver somehow managed to nominate themselves online through such systems only to be prosecuted for failing to name the driver.
A&S used to issue what is referred to as a SuperNIP - a combined NIP/s. 172 requirement/COFP (and possibly offer of SAC). Presumably when you say that you have accepted the NIP online, you mean that you have accepted either a COFP or SAC online?
I would strongly suggest reading the form thoroughly and ensuring that you have complied with the s. 172 requirements to name the driver.
As I said, case closed - thread can be too if anyone mods this forum.
As a general rule, threads being closed tend to coincide with posters being banned.