DH for 2017 - 2018 went over the £60k threshold so we paid our child benefit back. We've now been fined £2.5k for not doing the previous 2 years assessments when he was earning below £50k. I've looked at the paperwork we received and there weren't any clear instruction on us having to do this, it just said 'Self Assessment incomplete' for those years. We've paid the £2.5k fine
I'm not really looking for advice, this is more of a 'public service announcement' as the fact you have to do previous years doesn't appear as advice on places like Money Advice Service.