Amazon will soon start tacking on an extra fee for sellers who don’t use the company’s fulfillment service, according to reports from Bloomberg and CNBC. Documents viewed by the outlets indicate that Amazon will start imposing a fee on each product that merchants send out themselves.

The fee will reportedly go into effect on October 1st and will apply to the sellers who are members of Amazon’s Seller Fulfilled Prime (SFP) service. Unlike Fulfillment by Amazon (FBA), the SFP program lets third-party merchants sell Prime products directly from their own warehouses instead of having Amazon handle the logistics process. That means sellers are also required to keep up with Prime’s one- to two-day delivery standards and weekend shipping, CNBC notes.

While Amazon first introduced its SFP service in 2015, it shut down enrollment in 2019. The company didn’t reopen the waitlist until June of this year — a decision Bloomberg says Amazon made to satisfy regulators. It’s not clear why Amazon is imposing this fee now, and the company didn’t immediately respond to The Verge’s request for more information.

Still, the added charge could be a way for Amazon to nudge sellers toward using its in-house services, giving the company more control over the logistics process while letting it cash in on rising FBA costs. This may only result in increased scrutiny from regulators, as a seller already accused the company of forcing merchants to use its FBA service in 2019.