This scenario illustrates the "battle of the forms," where each party attempts to impose its own terms. The general legal principle is that the last set of terms sent before performance (in this case, Company B's invoice) takes precedence if the other party proceeds without objection (Company A's payment). Therefore, Company B's terms would likely govern the contract.
Reference:CIPS L4M3 Commercial Contracting Study Guide, Chapter 1, Section 1.2.3 - Principles relating to the battle of the forms and precedence of contract terms.

Once a valid acceptance takes place, a binding contract is formed. It is therefore important to know what constitutes a valid acceptance in order to establish if the parties are bound by the agreement. There are three main rules relating to acceptance:
1. The acceptance must be communicated to the offeree.
2. The terms of the acceptance must exactly match the terms of the offer.
3. The agreement must be certain.
Among the answers:
"The person says that she will think about it overnight" does not match the terms of the offer. The offeree does not assure that she will accept the offer.
"The person asks for a lower price": This is a counter-offer.
"The person states that she is able to pay the offered price" is not certain. The offeree merely provides information on her financial ability.
Reference:
- Contractual agreement - offer and acceptance
- CIPS study guide page 33-35
LO 1, AC 1.2

This scenario is in fact based on a famous case law: Dunlop Pneumatic Tyre Company v New Garage & Motor co [1915] AC 79. In this case law, the House of Lords identified the clause as liquidated damages, and therefore enforceable.
However, if this case had happened in 2015 or afterwards, there would be some legal issues:
- The price agreement is prohibited by Competition Act 1998
- If the agreement is allowed by Competition Act, as in the case Cavendish Square Holding BV (Appellant) v Talal El Makdessi (Respondent), the clause can also be identified as a penalty and it is still enforceable.
Reference: CIPS study guide page 158-159
LO 3, AC 3.2

Advantages of using fixed pricing arrangement are as below:
- Budget/income certainty - prices are fixed up front and should not change
- The impact of changes to the supplier's cost base is not fed through to the purchaser. If costs diminish, the supplier will benefit from this, and if costs rise, the purchaser will benefit Reference: CIPS study guide page 172-176 LO 3, AC 3.3

To write a strong, realistic specification for a renewal cleaning contract, good data sources include:
* Incumbent supplier (1): They can provide information on what has actually been delivered, issues experienced, and practical requirements.
* Alternative suppliers (3): Market engagement with other providers helps identify innovation, better methods, and realistic performance standards.
* Management information (4): Internal data (volumes, complaints, quality reports, site usage) shows what the organisation truly needs.
"Maintenance services" (2) are not inherently a good source for defining cleaning services requirements, so the best combination is 1, 3 and 4 only.
Reference: CIPS L4M3 Commercial Contracting - Developing specifications using management information, incumbent feedback, and market engagement.