UK CAA PPL Solo hours validity period
 

So i know that once all ground exams are finished there is a 2 year window to complete flight training and do the actual skills test but what if some of the solo hours were done in the last 10 years are they still good or have some of them expired? Is there a window for the solo hours to be within a defined period of time? I've searched the CAA site but I cant find it. If anyone has a link to a document to reference for this that would be brilliant but my searches so far have yielded nothing

I don't think there is any expiration date on hours, but I'm going by memory here so you'll need someone else to provide the proof (or lack thereof).

All training for a licence or rating must be completed at an ATO or now a DTO. The training organisation is required to certify all training that was provided by them. Similarly if you change organisations a certificate is required for any training conducted by another organisatioin. Your solo time is as good as the certificates that you can provide indicating where and when it was conducted. There was a point around 2012 where training conducted before that date was no longer acceptable.

I had a student few years ago with a similar case. It's like Whopity says. Certified by DTO/ATO and not before 2012.
I can't remember where was written but I definitely remember that the deadline was the year 2012.
It is always advisable to email the CAA and use that response from them as a support letter.

Another factor to note is:
Put simply, unless the Solo time is countersigned by the instructor who supervised it then you can't count it.

This makes for some difficulties. It has never been the case that a UK instructor has routinely countersigned each and every log book entry. The tradition in the UK has been to maintain a separate and comprehensive record, held by the school, although this might not always be the case outside the UK.

AMC1 FCL.050 instruction time: this doesn't actually state certification must be within the individuals logbook and entered at the time. The UK norm was for the CFI to certify the logbook as being a 'true record' whenever this was required. I still have my rubber stamp and ink pad for the purpose.

Logbook signatures for instructional flight
 

Thanks folks. All my solo flying was done within the last 6.5 years and I did change schools during that period (circa 6 years ago) and prior to that I got instructors to sign logbook acknowledging log book entries but as suggested I do have a certificate of training completed at previous school too so I think i'm covered in all angles. Currently been working on mock skills tests and had this convo with my instructor and he checked with other instructors and colleagues some of whom are examiners and the common answer among them all has been that they don't think there's any time period that solo flying needs to be within. The 2012 thing mentioned here I've not heard before so will be asking about that but as my solo flying was well after that I think I'm ok for that too but either way tis worth me asking