Short answer: No. But let’s look at a few specifics where you may be asked to pay.
First, there are companies that represent themselves as mystery shopping companies that can award shops, and they charge shoppers a membership fee or other charge to access available assignments. These are not mystery shopping companies. Mystery shopping companies do not charge you to apply. Never pay to apply, and never pay a “membership fee” to get mystery shopper jobs.
You do not need to pay to view available assignments. Sign up with as many mystery shopping companies as you can, and you will have more shop notices than you can handle. I have a list of 200 legitimate companies (none of them will charge you) here at MysteryShoppersManual.com. There are also job boards, such as Jobslinger.com, where you can view postings from many mystery shopping companies.
There are places that will charge you for a list of mystery shopping companies. You do not need to pay for a list. As mentioned above, I have a free list of 200 companies on this site. You can click through to as many as you like and submit applications to any or all of them. (It is not necessary to apply to all of them. You can pick and choose the ones you want to apply to, but there are lots to choose from.)
Why would someone consider paying for a list? I hear from a lot of people that all of the companies they find want to charge them. That indicates to me that they are doing an online search, then clicking on ads instead of the search results. In any case, my free list makes it easy to find legitimate companies.
What about paying for certification? The Mystery Shopping Providers Association offers certification programs, and they charge for them. Is this “paying to shop”? No, it is paying for education and a credential. It is not the same as paying a fee to register with a company. So is it something you need to do? Well, no. Certification is good. It can teach you about the industry and it can open doors with the MSPA companies that give preference to certified shoppers. It is a good thing, but it is not something that you must do to become a mystery shopper.
Before paying for any certification, be aware of who offers the certification and who recognizes it. Anyone can offer a certification, but it is not useful is no companies give an advantage to shoppers holding the certification. Although every mystery shopping company does not recognize the MSPA certification, many do.
Last but not least, I have written a book, The Mystery Shopper’s Manual. As much as it pains me to say this ;o) you do not need to buy my book to become a mystery shopper. I believe that the book will make your path easier because you will avoid a lot of problems and save time, but there is no requirement that you buy the book in order to become a shopper.
The bottom line is that you do not have to pay to become a mystery shopper. There are educational opportunities you may decide to pursue, but they are not required. You may also decide to purchase equipment, such as a digital voice recorder, that will make mystery shopping easier. But you can probably get started without purchasing any equipment at all. You do not have to spend money to become a mystery shopper.