The question that matters is who owns the trade discount.

Developers often ask what trade discount is standard. The market is happy to answer, because any number will do and none can be checked. The question that decides the project is a different one: when a supplier takes something off the price, whose money is it?

Published by ArtisDomus, written by Polina Surina.

That question has published answers, and more of them than most people expect. The designer’s own code, the architect’s regulator, the professional body, the criminal law on inducements and the rule in equity on secret commissions all address it. None of them names a percentage.

The BIID Code of Conduct of 1 April 2026 has ten principles, and four of them settle this question. Principle 2 requires the designer to act with integrity and avoid conflicts of interest. They must not knowingly accept any position where their personal interests conflict, or could reasonably be seen to conflict, with their professional duty (2(c)(i)). They must not accept payments or benefits that may, or could reasonably be seen to, impair their ability to stay impartial and transparent on behalf of clients (2(c)(iii)). If a conflict does arise, the designer must do one or more of three things (2(d)). They can disclose it in detail and in writing to all affected parties and get their written consent to continue. They can remove its cause and tell the parties how and why. Or they can end their involvement and tell the client why.

Principle 3 requires a written agreement before accepting or undertaking any professional work, and lists what it must cover. One item is the confirmed fee, or a detailed description of how the fee is calculated and retrieved. The word “retrieved” matters. It allows for a fee that reaches the designer by some route other than an invoice to the client, and requires that route to be written into the agreement.

Principle 5 covers client money. The designer must accurately record and account for all money they hold for the client or other third parties, at all times. They must arrange for interest or other benefits arising from the client’s money to be paid back to the client, unless the contract says otherwise. On request, the designer must provide clear records of purchases, expenses or fees. Principle 9(d) completes the picture: the designer must not offer or accept bribes or inducements, in line with the Bribery Act 2010.

Taken together, these four principles answer the trade discount question without a percentage. A reduction obtained while spending a client’s money is a benefit arising from the client’s money. The designer may keep it only if the written agreement includes it in how the fee is calculated and retrieved.

The Architects Registration Board issues the Architects Code. The 2025 edition came into force on 1 September 2025 and sets six standards. To meet Standard 1, honesty and integrity, architects use impartial judgment based on the evidence available. They declare and manage any conflicts of interest appropriately, and are transparent about any inducements offered or received. To meet Standard 4, professional practice, they give clients clear, understandable, written terms of engagement before starting work.

The RIBA Code of Practice of 1 April 2021 is more direct. Its guidance note is the passage to show anyone who thinks this subject is about envelopes of cash. Chartered Practices must not offer bribes or inducements, and must not accept them (clauses 6.1 and 6.2). The guidance to those clauses says that bribes “are not always direct offers of money, but instead may be more indirect gifts and incentives, including special offers of discounts on products, or special access to certain products”. It adds that there is no clear-cut line. The test is a matter of judgment on the facts, and the reasoning should be recorded in writing.

Clause 6.3 covers a gift or advantage meant to persuade the recipient to act against their own professional obligations. It also covers one meant to make them act against the interests of those to whom they owe a duty. A conflict of interest must be declared to all parties affected. Then its cause must be removed, or the practice must withdraw (clauses 3.1 and 3.2). The guidance to 6.1 and 6.2 does allow small gifts and hospitality in the normal course of business, provided their value could not exert an improper influence.

So a professional code names a discount on products as a possible inducement. No code says at what size it becomes one.

The Bribery Act 2010 applies without any public official or foreign contract. Section 1 covers offering, promising or giving a financial or other advantage, intending it to induce, or to reward, the improper performance of a relevant function or activity. Section 2 covers requesting, agreeing to receive or accepting such an advantage on the same terms. It makes no difference whether the advantage passes directly or through a third party (section 1(5) and section 2(5)).

Section 3 decides whether a design brief falls within the Act. A relevant function or activity includes any activity connected with a business or done in the course of a person’s employment. It also includes any activity by or on behalf of a body of persons. One of three conditions must also be met. Condition A: the person is expected to perform it in good faith. Condition B: they are expected to perform it impartially. Condition C: performing it puts them in a position of trust. Under section 3(7), business includes a trade or profession.

A designer or an architect choosing works for a client’s building is performing an activity connected with a business, and is expected to be impartial about it. That is condition B, and it brings a supplier’s rebate within the Act.

Equity, the judge-made rules on trust and loyalty, reaches a harder result by another route. In FHR European Ventures LLP v Cedar Capital Partners LLC the Supreme Court set out the starting point (paragraph 5). An agent owes the client, called the principal, a fiduciary duty, which is a duty of loyalty. It arises because the agent has undertaken to act for the principal in a relationship of trust and confidence. The agent must not profit from that trust, and must not put themselves where duty and interest may conflict. Consent counts only if it is informed and follows full disclosure. At paragraph 33 the Court stated the principle plainly. The agent owes a duty of undivided loyalty unless the principal has agreed to a less demanding standard. The principal is entitled to the entire benefit of the agent’s acts in the course of the agency.

The conclusion comes at paragraph 46: a bribe or secret commission accepted by an agent is held on trust for the principal. At paragraph 50 the Court treated three older cases, Tyrrell, Heiron and Lister, as overruled. The difference is practical. The client can trace a payment held on trust into whatever it was spent on. If the agent fails, the client ranks ahead of the agent’s unsecured creditors. A payment that only has to be accounted for gives the client none of this.

To avoid this, disclosure has to clear a high bar. Informed consent after full disclosure asks far more than a sentence in a proposal saying the designer may benefit from trade terms.

The design codes are the BIID Code of Conduct of 1 April 2026, the Architects Code 2025 and the RIBA Code of Practice of 2021. The art trade has the CINOA Code of Ethics, updated on 5 July 2024, and TEFAF’s terms and vetting pages. Art Basel has Exhibition Regulations for the Basel show of 2020 and the Miami Beach show of 2023. All of them set rules of conduct. None sets a price, a discount or a trade rate for anything.

Only one sentence in all of these touches the price of a work in an intermediary’s hands. Clause 20.5 of the Art Basel regulations for Miami Beach in December 2023 says the exhibitor may show only artworks it owns or is duly authorised to sell. That authority must come from the owner, and must cover offering and selling in the exhibitor’s own name, for the owner’s account, at the price the owner has approved. The clause settles who fixes the price. It is silent on what may come off it.

A supplier who quotes a designer a trade rate is describing their own commercial practice. A designer who repeats it to a client passes on a number that appears in no document. With no published standard to compare it against, a quoted rate cannot be checked.

This matters more on a project than in a gallery, because a project buys many works at once. A percentage across a whole scheme is a large sum dressed as a small number. The only way to know what it is worth is to see the seller’s own invoice.