The agency will require an authorised timesheet from you each week/month in order to be able to pay you. They will also need a claim for any expenses which your client is reimbursing you for (e.g. business mileage during the day). You should always send these as soon as possible after the week/month end.
Different agencies work in different ways. They may have an electronic timesheet system, or they may simply need you to send a hard copy of the timesheet to them by e-mail or fax. Make sure you find out from them what their process is.
It is better that as a minimum you inform us of the total of your hours for the week. This is because we may need to send an invoice to your agency for the hours.
We have an online portal where you can submit your hours.