If you require an invoice you can create one from your Settings page.
In the
top menu, hover over SETTINGS and choose Payments-Pricing-Billing

STEP 1: Enter the maximum number of Employees you anticipate during the
duration
STEP 2: Choose a duration option. The further you pay ahead
the lower the effective cost per month.
STEP 3: Click the Create Invoice button
You can then add additional information to the Invoice (P.O. number or
comments etc.) and click the Create Invoice button.
Your printable invoice will be displayed. You can then print it, save
it to your computer or e-mail it to your accounts payable department. You
also can send them a one page payment information pdf:
http://WhenToWork.com/paymentinfo.htm.
Note
you can also set up your accounts payable email address in your SETTINGS>My
Notifications tab so that they are notified 45, 30 and 10 days before the
account will expire.