What is the best way to include deductibles in an invoice (like CPP/QPP or EI)?

Mehran

I'm a self-employed contractor who uses WaveApps to issue my invoices. My new employer deducts CPP/QPP and EI from my invoices before the total payment. My question is, what is the best way to include these items in an invoice inside WaveApps?

P.S. I'm not sure if CPP/QPP and EI are calculated based on some percentage of the invoice total or what. I'm new to this.