Cotisations for coinjoint in auto-entrepreneur

You gave me some very good advice last year about switching from an EI business to being an auto-entrepreneur. It’s been a very slow process (tax office were rapid but URSSAF have taken 4+ months). I now have a form to fill in to decide on the basis of cotisations for my husband as conjoint collaborateur.

- Option A : contributions based on 58% of the real turnover you declare
- Option B : forfeitary option : the contributions are based on 58% of the plafond annuel sécurité sociale / 66%  -> so contributions would be based on approx 38660 euros of turnover.

It’s a tiny business and my turnover will be 10,000 or less. I’m guessing that option A is better, but my accountant hasn’t explained the differences and I’m not sure what the financial difference would be—if I opt for A—58% of my receipts – let’s say I make 10,000 – so based on 5,800 –what would the actual cotisation payment be?

Similarly, with option B, my accountant has simply said—58% of the plafond annuel sécurité sociale / 66% -> so contributions would be based on approx 38660 euros of turnover. I’m not sure where the 38660 euros figure comes from. But if it’s that—what would be the cotisation contribution figure on this option?

This will be on top of my own cotisations of 23% for services and around 14% I think for services so given it will be a small income I want to make sure I make the right choice.
Many thanks for your help
Cinnamon