Which statement differentiates supplemental services from additional services?

• A. Supplemental services are upfront and priced; additional services arise later and are billed hourly.
• B. Additional services arise later and are billed hourly; supplemental services are upfront and priced.
• C. Both are defined upfront and priced the same in the contract.
• D. Supplemental services are not billable.

Answer: (A)

The key idea is how these two service types are treated financially in the contract. Supplemental services are defined and priced upfront in the agreement, so the owner knows the cost for those extras before any work starts. Additional services, on the other hand, come up if the scope expands or new requests arise after work has begun, and they’re typically billed hourly (time and materials) as those needs occur. This upfront-versus-later, fixed-price-versus-hourly distinction is what differentiates the two. That’s why stating that supplemental services are upfront and priced and additional services arise later and are billed hourly best captures the difference.