Quote Assumption Change Log

A service quote assumes the client will supply clean data by June, the client later says it will arrive in August, and the quoted fee stays the same, so without a change log the delivery team may inherit a deadline that no longer fits the facts. List the original assumptions explicitly, since volumes, locations, integrations, operating hours and decision dates are common drivers, and a price with no supporting assumptions is difficult to revise fairly.

HubSpot's change-quote documentation describes changing terms of an active contract through a separate quote that captures differences, whereas a pre-contract assumption log is related but distinct because it records the basis for each proposed offer before acceptance. Proposify's project-proposal guidance emphasises clear scope and deliverables, and an assumption log supports that clarity when a proposal evolves across stakeholder conversations.

An illustrative completeness rate is revised quotes whose material changed assumptions are recorded and reviewed divided by all revised quotes with material input changes, so 45 of 50 gives 90%. Use one dated row per material change, recording the previous value, new value, source of information, potential price or schedule effect and reviewer, and do not silently edit the original basis.

Keep the customer wording where practical, because "up to 100 monthly orders" differs from "about 100 now, likely 300 next quarter", and a paraphrase that changes the limit can create a future dispute. Separate the input change from the commercial response, since a higher forecast volume may lead to a revised unit price but the log should show both the new assumption and how the offer was recalculated.

Identify unconfirmed assumptions, because sales estimates may be necessary to build a draft but should be labelled as estimates requiring customer validation before a final commitment. Track version and audience, since a revised quote sent to procurement may differ from a working draft discussed with an operations contact.

Check downstream effects, because delivery staffing, supplier capacity, implementation timing and support levels may change even when headline price does not. Avoid overlogging trivial edits, as a typo fixed in a contact name is not a material pricing assumption and a useful log focuses on factors that alter price, risk or delivery.

Coordinate with contract records, because once an offer is accepted the agreed scope and later amendments should control, and a pre-acceptance log does not itself modify a signed contract. Review exclusions too, since customers may believe an excluded service is included if a later proposal omits the earlier limitation, so note changes in exclusions as carefully as additions.

Watch timing, because a quote valid for a set period can be affected by later supplier costs or tax treatment and a new assumption should be source-checked rather than treated as a universal price rule. Use approvals proportionately, so a margin-sensitive change may need finance review while a schedule assumption may need delivery-team review, and check that the price table, scope section, implementation plan and customer email all reflect the same accepted assumptions before a quote is issued.

Preserve superseded versions and review missed assumptions after project completion, since rework or margin loss can reveal which inputs should be explicit in future quotes, and for an owner the log protects the link between promises and the facts used to price them without becoming an internal excuse for surprising the customer.