Advice about going self employed

[Syeface]

Hey guys, basically i'v just been taken on for a job in house rendering/dashing and im wanting a bit of advice regarding working tax credits and other things.
I'll list them for people who are reading rather than putting them into a paragraph:
1. The employer is going to be training me but says once i can do the profession he will employ me as self employed(Sub contracted), what does this actually mean?
2. The employer will be taking £20 per every £100 we earn to pay tax but im not sure if he will be paying my NI contributions and tax or just using the tax he takes from me to pay his own as he receives pay for his work fortnightly in a lump sum then pays wages and tax straight out of that... will i have to pay a further 20% tax ontop of what he already takes off of me for doing so?
3. Where will i stand with being able to claim Working Tax Credits? as i have a partner at home looking after the kids.
4. Sorry for being a pain in the rear end with my first post, im just really confused and not knowing what he means by self employed but the thought of just diving into it eyes closed is daunting to say the least.
I dont want to end up paying stupidly high amounts of tax twice (£100 tax for my wage £500 before Tax) leaving me £400 p/w and then another 20% off of that leaving me just £320, as £180 tax from a £500 wage seems pretty ridiculous at the best of times.

 

[Scalloway]

1. It means he is escaping some of his responsibilities as an employer
2. He should provide you with a document that allows you to set what he takes off with against the tax you are due so you do not lose out.

 

[Syeface]

Thanks for the reply,
What responsibilities is he escaping?
also, would he be paying the Tax/NI contributions for me? as i'v read somewhere that this is what he must do.

 

[Scalloway]

Paid holidays and statutory sick pay for a start. Also you may not be able to sue for unfair dismissal if he lets you go.

If you are self employed you must pay your own tax and NI

 

[Syeface]

So basically despite him taking £100 per week off of me for tax/ni, i would still have extra tax/ni to pay? seems kind of stupid considering tax would of been paid on the whole lump sum that the business owner is paid for the job he is working on at the time... gah this is really confusing to me

 

[Scalloway]

If he is taking money of you and you are on PAYE that is it - no more tax to pay. If you are self employed and he is taking tax off you that will be set against any self employed tax you are due.