Membership dues that are paid online through PayPal or Amazon Payments are automatically recorded in your group's Money tab if the Member paying the dues does so by clicking 'Pay Online' on your group's Home page.
But if you've received a dues payment as cash or a check, you can record these payments manually.
To do so, scroll over Group Tools, click on the Money tab and under All transactions select the Record a payment received link. Then click Membership Dues from the drop down menu. In the window that appears, begin typing a Member's name and select her profile from the drop-down menu. Enter the date of the payment, and the amount, and click Submit to add the payment to your Meetup Group's Money page.