IIRC time limit for service of NIP relates to it being sent to registered keeper. If it's a company or hire car then it's service at registered address that counts. If they're served in time and name your wife as driver then probably good service.

Minor mistakes can be corrected under 'slip rule' up to court date. Whether, if camera or evidence of observation by a constable is good enough, a slip over date is fatal probably needs proper legal advice for which you need to pay.

Some solicitors might give you a few minutes free over phone or local Citizens Advice might have 'pro-bono' appointments. Either will give an overview of whether you've a defence or if best to hope for offer of an driver improvement course.

Thanks Bromptonaut

It's our own car, not hired or company, and is dated 2 months after the alleged offence.

It's been sent to us at the address at which the car is registered.

I made an assumption that offence was in England. May be different in other parts of UK.

Sounds like they missed and are trying it on. Research legislation (Google is your friend) and ask them to justify late service else you'll take point in court.

Check the V5 registration document. Has it got your address exactly right? If not, that could be why you didn't receive the first copy, as this is almost certainly a reminder, although apparently some forces use the same format for original and reminder. Another possibility is that this is a leased car and the lease company is the registered keeper....

Next step - it is essential that the form is returned naming the driver unequivocally. If not the registered keeper - presumably your wife - commits an offence worth 6 points and a fine; and what's more your insurance company will be very unhappy and will raise your premiums.

In advance of this you might (a) phone the ticket office playing the bemused punter - try to find out why the form arrived so late; (b) why the date/day are confused; (c) ask for photographs to help identify the driver (NOT ask for evidence - critical point). The photo is unlikely to show the driver, to be honest, but may give you a clue as to the detail of the alleged offence.