Rates where the Money Back Guarantees option is used

I have read several other posts on Money Back Guarantees, but none address my question, which is related to expense budgeting.

We will be offering a service where we represent the interests of third parties, where clients can buy a service offering for a fee.

We will offer a money-back guarantee, what rates should I expect clients to exercise the money back guarantee option? Is it relatively small, like 2-3% of the time, or is it higher, like 10% of the time?

Since our company will absorb the transaction fee, say 6% and there is a 10% return rate, then my actual credit card expense rate is 6.6% of sales. Our fees will have to be high enough to compensate, otherwise we won't make enough to cover our expenses and make a profit.

What's a reasonable number to plan for?

Also, are there any strategies that can help minimize the need to exercise the option, if we cannot guarantee the quality of the work our third parties might offer?

Thanks,
- El

Money back guarantee because of the quality of work of 3rd parties has to be at the expense of said 3rd parties.

You have to do your market research to know what's the rate of exercising your option. How can you ask that without telling what kind of service or product you're talking about?

But, if you have different providers, you can set different fees (updated frequently enough to adjust) that would take into the account the exercise statistics of the specific provider. If one provider gets 1 client per 1000 to exercise the option, and the other one gets 1 client per 10, you obviously have to charge the second one much higher fees than the first one (if carry them at all). You should also consider a reimbursement agreement with your providers, to share the risk.

If you have different kinds of providers from different areas or market segments - you need to research each such segment and set default rate per segment.