Singapore is a single unified jurisdiction, so unlike a multi-state contract the service agreement does not vary by province or state. What does vary is the type of director and the type of company, and the agreement must be tuned to both.
Executive directors carry the full weight of an employment relationship layered on top of their office, so their agreements engage the Employment Act 1968 where the individual falls within its coverage, together with all the section 157 fiduciary duties. The contract here is the fullest version, with remuneration, notice, leave and restrictive covenants all documented. Non-executive and nominee directors sit at the other end. They are generally engaged under a short letter of appointment rather than a service agreement, because there is no salary or day-to-day management to govern, and a nominee director in particular must preserve independent judgment despite the wishes of an appointor.
Company type shifts the emphasis too. In a Pte Ltd with a tight shareholder base, the service agreement is usually read alongside the constitution and the members' arrangements, and the reserved-matters list in those documents constrains what the director may decide alone. The company must maintain at least one director ordinarily resident in Singapore under section 145(1), a requirement the appointment should never inadvertently breach, and it must have appointed a company secretary within six months of incorporation. Companies limited by guarantee and larger groups add further governance layers, but the drafting principle holds throughout: the director's contractual powers must match the authority the constitution actually confers. Where the wider incorporation paperwork still needs assembling, our Singapore Pte Ltd incorporation pack covers the founding filings that precede any service agreement.