Moving from a signed Wedding Photography Contract to terms and conditions

http://www.consumeraffairs.govt.nz/for-consumers/services/contracts

If I understand the information in the link above correctly services such as wedding photography do not require a signed contract. The only contracts that require signatures are:

• consumer credit contracts
• door-to-door sales contracts 
• contracts agreeing to act as a guarantor 
• contracts for the purchase of a motor vehicle from a dealer 
• contracts for the purchase of real estate.

None of those are wedding photography. Yay!