The complexity of the contract will reflect the complexity of the purchase. For simple, low-value purchases, standard terms and conditions may be all that is required, but do not assume that just because the purchase is one-off, the contract will be simple. It may still need to cover the following areas:

- Warranties and guarantees if the one-off purchase has a considerable life-span and is business-critical (e.g., a back-up generator for the office which houses the national computer servers).

- Insurance requirements: including professional indemnity, public/products liability, employer's liability, and cover for any specific risks such as pollution or working at height.

- Specification requirements on quality, timing and delivery

- Minimum quality standards on the business operation (e.g., a catering provider might only be providing sandwiches for a team meeting lunch, but you still need to know its hygiene practices).

- Built-in change process for any goods or services that are beyond very simple (e.g., works contracts always have variations procedures because of the unpredictable nature of such projects).

- Ability to extend the scope of the contract should be minimal or none, and restrained to the single requirement.

- Ability to extend the duration of the contract should be limited to the ability to accommodate unexpected time overruns (which itself should be subject to a damages/penalty provision where they are attributable to the supplier, and an extension to overheads costs where they are attributable to the purchaser).

- Data security protocols need to be considered if personal data is being shared.