This is a great question and a common one.  First of all, many organizations already have a clause in their sub-contracts where the contractor has agreed to use company-specified or company-provided systems.  It’s quite a common aspect of a sub-contract and is needed for many reasons.  If you’re using access cards for your front door, for example, contractors absolutely must comply with having an authorized access card in order to work.  The same logic can be applied to other systems.  It is relatively simple to insist that contractors use your internal timesheet system.  That being said, there are two things you may find are immediate concerns and TimeControl can handle both of them:

1. Can you separate the access to data by the sub-contractors so they only see things that are appropriate to them and they can’t see things from either the company or other contractors?   TimeControl’s User Profiles allows you to set filters for many purposes including this exact scenario.  You can isolate the data for the sub-contractor to see as much or as little data as desired.
2. Can you create an approval mechanism for contractors that is distinct from other contractors and from the company?   TimeControl’s flexible approval mechanism allows you to design an approval for each sub-contractor so they can be involved in the approval mechanism and you can insert people such as a contract manager into the approval mechanism for them.

The benefits of having both your internal personnel and your contracting personnel on the same timesheet system can be significant.  There is a use-case section of the TimeControl website dedicated to this with a webcast, white paper and other resources located at: www.timecontrol.com/use-cases/manage-contractors.