How is Social Security & Income Tax calculated if I am a MICRO-BIC <<REAL SIMPLE>>?

[Alex Duncan]

I am registered under the MICRO BIC / "Real Simple" regime. I run a B&B/Gites. But I susspect that I haven't correctly understood exactly how my SS and INCOME TAX are calculated from the GROSS REVENUE that I declare. Could someone please help me understand - for example a simple hypothetical calculation based on say 50,000 Euros = My B&B/Gites Revenue (the money I get payed by my clients).

I am not to concerned about the TAX - as far as I can see, they deduct 72% off the revenue then from the 28% that is left, work out my TAX. For example TAX would be about 25% of 28% of 50,000.

What I am concerned about is SS. I know that SS works out at about 40 - 60 % of one's 'salery'. Here is my dilema! Please don't tell me that I am going to loose 40-60% of my revenue (the 50,000) to SS? I thought - and I fear I have made an error - that SS was going to be calculated on a lesser figure than the otal revenue - like maybe : revenue - 72 or 68%.

I tell you - I thought I understood my accountant - but perhaps not Please help if you can. I tried to find a simple calulation example online - but failed.

Many thanks. Alex (Cevennes Mountains, France).