What the Consumer Guarantees Act 1993 (the CGA) does is insert some basic guarantees into every contract for the supply of consumer goods or services, and those guarantees override anything that the written contract might say to the contrary. This is important because large suppliers often impose standard form terms of trade on their customers that are heavily weighted in the suppliers' favour, and a small customer has no chance of negotiating anything more favourable.
The CGA only applies if you are supplying goods or services to "consumers". However consumers are defined as individuals, companies, Councils, clubs or other legal entities who acquire goods or services "of a kind that are ordinarily acquired for personal, domestic, or household use or consumption". So it is the nature of the product or service being acquired that is important. The only things clearly outside the ambit of the CGA are those that would rarely or never be acquired for household use, such as dentistry equipment, bulldozers, business management software and military hardware.
Therefore the CGA can equally apply to business-to-business sales as long as the product or service is of a kind that is ordinarily acquired for personal, domestic, or household use or consumption. But there are some exceptions. They are sales of goods or services to customers who acquire them for the purpose of re-supplying them in trade, consuming them in the course of production or manufacture, or (in the case of goods) carrying on a business of repairing or treating other goods or fixtures on land. Those customers are excluded from the definition of "consumer".
If the transaction in question is not caught by one of those exceptions then the business seller and buyer can still contract out of the CGA, as long as they do so in writing. A sophisticated supplier's terms of trade are invariably going to do that, so you might think you are stuck. But the CGA allows this only if it is "fair and reasonable" to do so. The fair and reasonable requirement leaves it open for a small business to ask a Court to enforce the CGA's remedies against a powerful supplier, even though the supplier's terms of trade exclude the CGA. So if you are in that situation, don't give up hope. If it is worth going to court for, you have every chance of succeeding.