To receive the full state pension in the UK you need to have paid thirty years worth of National Insurance contributions (a specific, earnings related tax).
People often go out of their way to cheat on taxes or avoid paying them in someway but forget about the future implications where their lack of record of earnings and contributions can come back to bite them.
Not that anyone should really rely on government promises when it comes to pensions, as most are really complete Ponzi schemes and largely unsustainable. Which of course makes doing your own planning for your own future all the more critical.
I posted about Retirement Planning for ex-JWs