Soo. I bought a frame with a few big ideas in mind. V5 has just turned up and the numbers aren't quite right.

NC31***696 is the frame number on the v5.
NC30-****696 Is the frame number

So it's either an error in print with a missing 0
NC3(0) ****696

Or I've got a v5 for an cb400. But 6 digits seems too little after a preliminary google on the subject.
NC31 ***696

So they have either missed a letter? Does that happen? I know errors occur especially with these imports. One of my old nc23s had the frame number starting nc23e on the v5. The other numbers matched and I knew it was just confusion between the frame and engine at some point. So never worried. But this seems a little bit more odd.

What should i do now?

take it to your local DVLA office...get them to issue a new V5..simples.

So you think Its just an error and not something dodgy?

It must be an error - easily done.

I edited out the number just incase there are some unscrupulous folk viewing.

Anyhow.

It sounds like a simple error, take the V5 to the nearest DVLA office, phone them if you have all day and youll get it sorted.

If they were totally different then I'd suspect that soethign was up but for them to be only 1 number short implys a bad typin up, easily done, easily fixed.

I'd get it sorted. It's not entirely impossible that they'll want you to take the bike to a local inspection facility so that they can check the numbers on the frame and the engine match those you have given them. If it were me, I'd be paranoid about some pen-pusher using that fact to invalidate my insurance or fining me for having incorrect docs on the bike!

I had an NL30 for a while... lol

the easiest way is if you have old MOTs that have the full VIN no on them.
I have had a similar issue on my Ducati Superlight. When Duke's of that age (1994) were registered it was often done with the just the 6 digit 'serial no' not the full 17 digit VIN. I've had the bike 11years, but decided to HPi it last year as I've done with everything else I own/owned. Came back as Cat C 2 years AFTER i'd bought it. Turns out the Cat C applies to a 2005 Peugeot 406/7. Let's say it's VIN is ABCDEFG123456789 (17 digits) but my bike only had the last 6 digits recorded on my V5 and they were say 456789 then that's why my bike get's flagged as Cat C. Because my VIN no totally fits within that of the written off vehicle.
To cut a long story short DVLA wanted an Inspection to create the V5 with the full VIN No stamped on the frame, until i mentioned I had some old MOTs which had written on them the full VIN, they accepted this as proof and I now have the V5 corrected
You can just imagine how pi55ed I was to find my bike was written off 2 years after I bought it, when it had been wrapped up in the kitchen most of the time!

Damn. The owner gave me some old mots and service history. I never bothered looking at since I'd just bought the frame haha. Just dug them out and the number is wrong on them too ahhhh. Still missing the zero in 30. A bit worrying. Getting the frame anywhere is hard cos I don't drive and strapping it on the back on the 7r wouldn't be a good plan aha.

can you not take a pic of the frame numbers and go to visit your local DVLA office?

You can also amend the V5 - send it off with a number change?