Whoaaaa. If the letter/NIP is addressed to your wife and it was you driving, then SHE must fill it in nominating you as the driver. The rozzers will then send YOU your own NIP with your name on it. You cannot use her form to claim you were driving.
She has 28 days to respond and supply all the requested information - in this case by nominating the driver (i.e. You). Normal Pepipoo advice is to wait until about day 25 to respond. Take it to a Post Office, pay for a 1st class stamp, and get proof of posting and keep it. Do not miss the 28 day deadline.
Yes...I know all that, but thanks anyway. Mine, sorry, the wife's, form will be posted tomorrow by me. Why wait 25 days to send it off? It's a poxy course that's got to be done no matter when you send the letter back.
Never heard of pepicrap though
You wait 25 days because the rozzers have several time deadlines that they have to meet in order to be able to successfully prosecute you.
The first deadline is that they have to serve the NIP on the registered keeper (RK) within 14 days of the date of the offense. They get the RK details from DVLA. However, where there has been a recent change of keeper things can get tricky. They might have served the notice on the previous owner, or the dealer. In either case, the dealer/previous owner would have nominated your wife, and then the rozzers wrote to her. Or if the DVLA details had been updated promptly, then your wife may have the first to receive a NIP.
So basically, what was the date of the offense, what is the date on the NIP, and on what date did she receive the NIP? Also what sort of postage was on the envelope - 1st class?
The next deadline is that papers have to be laid before the courts within 6 months of the date of an offense for a crime to be tried by magistrates. So suppose they issued NIP #1 to the original owner (2 weeks) who replied promptly (1 week) saying I sold the car to "Arfur Daley Motors inc". The scamera pratnership take a week to send NIP #2 to "Arfur Daley Motors inc", who promptly reply (1 week) nominating your wife. So we're now 5 weeks into the 6 months (26 weeks).
The scamera pratnership take a week to send a NIP #3 to your wife. Your wife then has 4 weeks to reply which she takes. So we're now 10 weeks in.
The scamera pratnership take a week to send a NIP #4 to you. You then have 4 weeks to reply grassing yourself up, which you take. So we're now 15 weeks in.
The scamera pratnership take a week to send a CoFP/Course to you. You then have 4 weeks to reply, which you take. So we're now 20 weeks in.
There are an awful lot of ifs and buts, but by doing the above you are giving the scamera pratnership every opportunity to screw up. It only take a week or too here and there for them to run out of time to lay the papers - and you are doing nothing wrong.