The contractual documentation is often the best starting point for resolving a dispute as to an individual's employment status and the tribunal will not generally consider extraneous evidence unless the contract is clearly a sham or there is evidence that the parties did not intend the document to be an exclusive record of the relationship. However, there are often cases where the contract has been varied over time or it no longer reflects the reality of the arrangements between the parties. Further, there may be instances, as in the recent EAT decision of MOD HQ Dental Service v Kettle, where the written agreement mis-states key features of what the parties have agreed either by mistake or by reason of misrepresentation such that it would be inappropriate to rely exclusively on the written agreement to determine employment status. Ms Kettle was engaged by the MOD under a contract for the provision of consultant orthodontic services. However this contract was accompanied by an "invitation to tender" more akin to a tendering process where a contract is awarded to a contractor running their own business. The EAT agreed that the written contractual documentation was clearly inappropriate for the engagement of a single practitioner and the tribunal was entitled to look beyond the terms of a contract at the overall picture. Whilst the individual paid her own tax and national insurance, received no pension or sick pay and had to provide her own insurance against negligence (all of which seemed, on the face of it, to indicate self-employed status), the original job advertisement suggested an employment relationship, she worked regular weekly sessions at MOD clinics, had lists of patients, an MOD uniform and the MOD provided cover when she was on holiday. The EAT upheld the tribunal's decision that Ms Kettle was an employee as there was mutuality of obligation, control and personal service (the "multiple test" established in Ready-Mixed Concrete (South East) v Minister of Pensions and National Insurance (1982) applied). Weight was placed on the fact that Ms Kettle was always part of the MOD system, subject to their direction and control, used their equipment and never provided a substitute. (Ministry of Defence HQ Defence Dental Service v Kettle).

Companies should ensure that there is consistency between advertisements and contractual documentation used to engage staff or contractors. If it is intended that the contract will be an exclusive record of the terms of the agreement, the contract must be appropriate and reflect reality.