UC & carer allowance

Hello all
We are in receipt of UC, now twisted thing is when we applied I had EU fam member 5 year residency, but they refused to add my component in UC around £170 or something because I was dependent on my eea partner.
I did not question them but they still put my name as it went as joint claim,
My monthly income has been around £300 as only working part time because of being carer full time.
I never applied carer but I'm planning on applying carer now and telling UC that I got ILR so they will(should) add my component they refused last year

My question is,
If my carer is awarded would they take same amount off UC ? They currently charge 63p every £1 if my income goes over 280
Would this threshold be same if I get carer and add my component or reduced,
Please help as I got ILR 3 months ago so don't want to miss on back date payments

There is no need to apply for CA separately, the only benefit of doing so is that it can be backdated up to 3 months. CA is deducted on a £ for £ basis from UC. However, if you are entitled to CA (whether or not you claim it), then there will be a carer’s addition of ~£160.20 per months, it’s that figure which you will better off per month. If CA is backdated 3 months (£123 per week earnings limit), then insofar as you were receiving UC in that period and passed the HRT, you should receive the carer’s addition, backdated for that period too.

Is it your partner that you are a carer for? Do you have dep children?