It’s one thing if you receive bonuses from your suppliers, but somewhat different if you’re the one paying bonuses. Those are the bonuses you calculate on the bases that you’ve determined with your clients and they’re the ones that decrease your profits at the end. 

Bonuses you pay to your customers are calculated on the bases that you’ve determined and agreed with your clients, and paid for the period you find suits you – month, quarter or a year. Obviously it’s an agreement, but normally you do have an upper hand in this deal.

Anyhow, as to accounting treatment, bonuses paid to clients are decreasing your profits, but not through an expense account through your regular expenses. It’s an expense account all right, but it’s part of your sales revenue. Why you ask? Well, because bonuses paid to your suppliers are sales bonuses and as such, you’ve essentially received less revenue. Albeit if you’re the one actually paying the bonus and it’s not taken directly off from every sales invoice at the spot, it’s still showing as a decrease in sales revenue.

And obviously, do keep in mind that if the bonus relates to the period X, it needs to be recognized within the results of period X