Free Traffic Legal Advice

So have you looked at the V5C and confirmed that the details are correct?

The s. 172 requirement incorporated into the NIP isn't invalid under these circumstance, and the driver still needs to be named.

However, if the police have failed to serve the NIP on the registered keeper within 14 days, and there are no issues with details, then any prosecution should be barred by S1 Road Traffic Offenders Act

It is possible that what you have is not the first NIP, but a reminder, reminders are only rarely labelled as such and look identical to a first instance document. It would be advisable to make 'a bemused phone call' querying the apparent lateness.

Who knows? And who cares?

Unless/until the OP comes back and fills in the blanks, everything is just idle speculation and noise.

The reason we know that it's not a reminder has absolutely nothing to do with whether or not some original 28 days had expired or not - some forces apparently send out reminders before the 28 days has expired - technically a "reminder" after the s. 172 offence has already been committed is not a reminder but a second chance. It does however, have everything to do with the fact that they sent the OP a letter at the same time telling him that his details on the V5C were incorrect.

In general, a NIP issued "late" to an RK is likely to be a reminder. In the instant case the police appear to be saying that the OP is effectively not the RK (the vehicle is not correctly registered in his name and address).