Amazon Boosts Monthly Prime Membership Fee has boosted the fee paid by Prime members who pay month by month to $12.99.

The fee was previously $10.99. Amazon introduced the monthly payment option in part to lure more lower-income shoppers into becoming Prime customers, whose benefit includes free delivery and access to the company’s entertainment portfolio. Although those customers will see an 18% price rise, the fee for Prime members who pay on an annual basis will continue be $99 per year.

The timing of the Prime price rise coincides with implementation of the recent federal tax cut.