Benifits

[JustMeAndMyBaby]

Is there any benefits you can get while setting up as self employed?

Income support if you are earning under a set amount. Wtc if you are 16+ hours & under a set wage.

How do you prove what you are earning if your only starting?

Don't know. If you keep accounts then I suppose you could use these/bank statements but I'm not sure what they would accept.
10 years ago I did some SE work on top of my main job & no one queried it but they might be tighter noe

I think you initially predict what you expect to earn for the 1st year on WTC, at the end of the financial year you give them your actual figures for incoming/ outgoing amounts (invoices, receipts, bills etc)

If there's a big difference between predicted and actual figures they either adjust the following years' WTC or do it via a lump sum - I'm not sure which..

You estimate up front
and then submit your SA return to get it put straight in arrears
NEVER send in invoices etc : even HMRC do not want to see them

Yes. NEA (New Enterprise Allowance) - somehow linked with WTC.