Immigrationboards.com

Apologies in advance if this is a repeat post or sent under the wrong category.

My query is - How soon we can renew the British passport? Reason - I read somewhere that after 50 years of age, the passport is issued for 5 years rather than 10 years. If that is the case - I will be 50 in 3 months and my password is expiring in August'26. Can I apply now so that I can get the validity for 10 years?  

Thanks in advance for any advice on this.

There is no such rule. You have either misread or it is relevant to another country passport.