Now if you have come this far, many of you might be wondering what do you actually mean by all these jargons such as contract of/for services, agency legislation, etc and how can you ensure that your contract with the agency complies with it. Well its all pretty simple but first I need to explain what all these terms mean as having firm grip of these policies is crucial to ensure that your agency contract complies with it.
AGENCY LAW:
If you are subjected to (or to a right of) any supervision, direction, or control as to the manner in which you provide your services during your arrangement/contract, you are subjected to agency legislation. Generally it is considered as 'Contract of Services' as you are working in a manner/relationship of employee of that business although on papers you are a contractor.
However if you are given a free role to complete your task with no one being able to intervene to instruct/manage how the task must be created or look like. The only specific requirement placed on you is that the task for which you are being contracted must be completed and activated before your engagement ends. Generally it is considered as 'Contract for services'
Working at client bases doesn't have to do anything with agency law. You may work at client base throughout ur engagement and will not be subjected to agency legislation/contract of services unless you are not subjected to supervision, direction, or control at client base.
To look deeper into agency legislation, please go through the following link:
http://www.hmrc.gov.uk/manuals/esmmanual/esm2029.htm
At this point if you have understood the concept of agency legislation the next big question for many would be how are you supposed to ensure or request you agency to come up with clauses that make you contract compliant with agency legislation (contract for services). Well the good news is 95% of contracts are already compliant with agency legislation. It must include the clauses complying to agency legislation and clearly state that the agency has engaged you in a contract for services. That is because agency legislation/contract for services is not specifically designed for Tier 1 entrepreneurs, but in fact it's designed for all agency contractors irrespective of his/her status. In short, either a contractor is in Tier 1 category or he/she is a UK/EU citizen, all of them along with their agencies have to comply with it. In case an agency is unable to comply with the legislation then it becomes a relationship of employer/employee (contract of services) b/w the agency and contractor and the agency is supposed run payroll/PAYE for its contractor.
Since its a requirement imposed by HMRC on everyone irrespective of his visa status, you don't need to worry about your contract at all. You just need to confirm that its a agency legislation compliant contract. As for the agencies which are unaware of this categories, you need to explain them that you are fully allowed to work as a contractor unless its contract for services (agency legislation compliant) and use the above references. Since agencies are already in the business of designing agency legislation compliant contracts, they will treat you and your contract the same way.