Last updated 4 October 2026 — by Adrian Tan, SDM. Marketing guidance, not legal advice. If you are unsure whether a title or claim is permitted, check with the Board of Architects, the Professional Engineers Board or ACRA before you publish.
Most marketing rules in Singapore are about what an advertisement says. For three professions, the first rule is about who is allowed to say it. Calling your business an “architectural” studio, putting “Er.” before a name on a LinkedIn profile, or describing a bookkeeping service as “public accounting” are each criminal offences if the person or firm behind them is not registered. None of these require a complaint about misleading content. The title alone is the offence.
That makes these rules unusually relevant to people outside the professions: interior design and renovation firms, design-and-build contractors, engineering consultancies with unregistered staff, and accounting and corporate-services firms. This guide covers the title and holding-out offences first, because they catch the most businesses, then the publicity codes that bind registered architects, professional engineers and public accountants, and finally what an agency running their campaigns needs to know. Law firms have their own, stricter regime, which we cover separately in our guide to law firm advertising rules in Singapore.
Who may call themselves an architect
Section 10(3) of the Architects Act 1991 is the provision design businesses most often run into. Unless you are a registered architect holding a practising certificate, or a licensed corporation or partnership authorised to supply architectural services, you must not:
- use the word “architect” or any of its derivatives in your business designation, or any name likely to make people believe you are an architect (s 10(3)(a));
- advertise or hold yourself out as authorised to supply architectural services in Singapore (s 10(3)(b));
- use “architect” or its derivatives in the name of a practice unless authorised (s 10(3)(c)); or
- use “Architect” or “Ar.” as a title before your name (s 10(3)(d)).
Section 10(5) separately prohibits supplying, or offering to supply, architectural services without authority. Builders have a carve-out in s 10(5A), but only where the architectural services are actually provided by a registered architect or licensed body.
Why this matters to interior design and renovation firms
Section 13 of the Act allows unregistered people to carry out construction or repair work where no plans have to be submitted to a building authority. Most interior and renovation work falls into that space, which is why the industry operates freely without architects. But s 13 permits the work; it does not permit the title. A renovation firm that does entirely lawful work can still commit an offence by describing itself, its designers or its services using the word “architect” or its derivatives.
The Board of Architects’ FAQ restates the point. In marketing terms, the risk sits in places nobody treats as advertising copy: the registered business name, the Google Business Profile category, a designer’s job title on Instagram or LinkedIn, an SEO page targeting “architect Singapore”, or a portfolio headline calling a home “architect-designed”. Because the Act reaches derivatives and any name likely to mislead, descriptors built on the word carry risk even when qualified by another word. If a title you want to use contains it, ask the Board before you print it.
The commercial consequence most firms miss
Section 11 adds a sting that has nothing to do with prosecution: a person who supplies architectural services without authority cannot sue to recover fees for them, and a client who paid without knowing the supplier was unauthorised can recover the money. A firm that markets itself as providing architectural services, and then delivers something a client later disputes, may find its marketing has undermined its own invoice.
Who may call themselves a professional engineer
The Professional Engineers Act 1991 follows the same pattern in s 15. Only a registered professional engineer may use “professional engineer” or any derivative, or the titles “Engineer”, “Er.” or “Engr.” before their name, or any description implying registration (s 15(4)). It is an offence to advertise or hold yourself out as authorised to supply professional engineering services in a prescribed branch of engineering without the right authorisation (s 15(6)), and to supply or offer those services without it (s 15(8)).
The word “engineer” is far more common in ordinary job titles than “architect”, so the practical line is the honorific and the claim of registration, not the word itself in every context. Where marketing goes wrong is in implied registration: a consultancy’s website calling its whole team “our engineers” beside a “PE-endorsed” badge when only one director is registered, or a contractor’s ad offering to “certify” or “endorse” work that only a PE may sign. The penalty scale in s 15(10) mirrors the architects’: a fine of up to $5,000, and for a repeat offender up to $10,000 and/or six months’ imprisonment.
Who may call themselves a public accountant or chartered accountant
Accountancy has two protected titles, under two different Acts, and they are often confused.
“Public accountant” — Accountants Act 2004, s 56
An unregistered person must not practise as a public accountant, hold out as one, or advertise any title or description implying registration or authority to provide public accountancy services (s 56(1)). A company that is not an approved accounting corporation must not use “Public Accounting Corporation” or “PAC” in its name (s 56(2)(c)), with equivalent bars for firms and LLPs (s 56(3)–(4)). The penalty under s 56(6) is a fine of up to $5,000 and/or imprisonment of up to 12 months, with higher maximums for repeat offenders.
ACRA is clear about the boundary: general accounting, tax, bookkeeping and advisory work do not require registration as a public accountant. Public accountancy is essentially statutory audit. So a bookkeeping or corporate-services firm may advertise everything it actually does; what it must not do is describe itself in terms that suggest it can sign audits.
“CA (Singapore)” — ACRA Act 2004, s 35B
Since 1 April 2023, when the Singapore Accountancy Commission merged into ACRA, the chartered accountant designation has been protected by s 35B of the ACRA Act. It is an offence to use “Chartered Accountant of Singapore”, “CA (Singapore)”, their derivatives or abbreviations in any language, or any description implying the designation, unless registered. ISCA confers the designation and requires active membership to use it. The penalty under s 35B(5) is a fine of up to $5,000, and for a repeat individual offender up to $10,000 and/or six months’ imprisonment.
For marketing, that means the post-nominal on a team page, an email signature or a LinkedIn headline is a regulated claim. If a team member’s membership lapses, the designation has to come off every profile that the firm controls.
What registered professionals may say in their ads
Being registered is the entry ticket. Each profession then has a conduct code that governs what its publicity may contain. All three apply to online channels.
Architects: the most detailed code
The Schedule to the Architects (Professional Conduct and Ethics) Rules defines “publicity” to include any advertisement in any medium, electronic included (para 1). Paragraph 5 then sets the rules:
- The general test. An architect may publicise the practice, but nothing that is misleading, deceptive, inaccurate, false or undignified, or that the Board has pronounced undesirable (para 5(1)–(3)).
- What “misleading” includes. A material misrepresentation or omission, unverifiable information, and anything likely to create an unjustified expectation of results (para 5(4)). “Singapore’s most trusted architects” and “guaranteed approval” both fail this test.
- Expertise claims must be justified by qualifications, experience, resources and capacity (para 5(5)–(6)).
- No comparison or criticism of another architect’s fees or quality.
- Portfolio honesty. No mention of projects the architect did not work on; none that would breach client confidentiality; and any project mentioned must state the architect’s own role and credit other architects involved.
- Responsibility for others’ publicity. The architect is responsible for publicity done on their behalf, including by agencies, must get improper publicity withdrawn, and cannot delegate that duty (paras 5(7)–(9)).
Other paragraphs prohibit touting and paying for introductions (para 6), permit publishing one’s own work but not soliciting advertisements for that publication (paras 7–8), limit name boards on buildings to the “unostentatious” (para 9), and bar supplanting another architect or competing by cutting fees (para 11).
Professional engineers: the same tests, plus a product rule
The Schedule to the Professional Engineers (Code of Professional Conduct and Ethics) Rules expressly includes the internet in “publicity” (para 1) and applies the same misleading-publicity tests as the architects’ code (para 2(3)–(4)). Expertise claims must be justified by qualifications, experience, facilities, personnel and capacity (para 2(5)–(6)); there must be no confidentiality-breaching mention of past projects or clients, and no comparison with or criticism of other PEs or allied professionals.
The distinctive rule is para 2(10): a PE must not endorse engineering products or processes in any commercial advertisement. That matters to manufacturers and suppliers as much as to engineers. A waterproofing brand cannot run a campaign built on a named PE’s endorsement, however genuine. The code also bars canvassing or soliciting work and paying for introductions (para 8), and supplanting another PE (para 6).
Public accountants: one short rule, broadly drawn
The ACRA Code of Professional Conduct and Ethics, made binding by the Accountants (Prescribed Standards and Code of Professional Conduct and Ethics) Order 2023, deals with marketing in R115.2. A public accountant must not bring the profession into disrepute when marketing; must be honest and truthful; and must not make exaggerated claims about services, qualifications or experience, disparaging references, or unsubstantiated comparisons with the work of others. Application material 115.2 A1 suggests consulting the professional body when in doubt.
Two points often surprise firms. First, there is no ban on advertising fees: quoting a lower fee than another accountant is expressly “not in itself unethical” (330.3 A2), although a very low fee raises a question about competence. Second, referral fees and commissions are not banned outright; the Code treats them as a self-interest threat to be managed (330.5 A1).
The three professions side by side
| Rule | Architects | Professional engineers | Public accountants |
|---|---|---|---|
| Protected title | “Architect”, derivatives, “Ar.” (s 10(3)) | “Professional engineer”, derivatives, “Er.”, “Engr.” (s 15(4)) | “Public accountant”, “PAC” (s 56); “CA (Singapore)” (ACRA Act s 35B) |
| Holding-out offence | Yes, s 10(3)(b) | Yes, s 15(6) | Yes, s 56(1) |
| Fine for misuse (first offence) | Up to $5,000 | Up to $5,000 | Up to $5,000 and/or 12 months |
| Unverifiable or results claims | Prohibited, para 5(4) | Prohibited, para 2(4) | No exaggerated claims, R115.2 |
| Comparisons with peers | No fee or quality comparisons | No comparison or criticism | No unsubstantiated comparisons |
| Fee competition | No competing by cutting fees, para 11 | No supplanting, para 6 | Lower fee quotes allowed, 330.3 A2 |
| Endorsing products | Not specifically addressed | Prohibited in commercial ads, para 2(10) | Not specifically addressed |
| Liability for agency’s publicity | Yes, non-delegable, para 5(7)–(9) | Covered by the general publicity duty | Covered by R115.2 |
Two premises we tested and could not support: none of the three codes contains an express ban on testimonials, and none regulates award claims specifically. Both are caught instead by the general tests — unverifiable information and unjustified expectations for architects and engineers, exaggerated claims for accountants. A testimonial promising a result, or an award badge that cannot be verified, can fail those tests.
Six campaigns, checked
- A renovation firm’s Google Ads targeting “architect Singapore”. Bidding on the keyword is not itself holding out, but an ad headline or landing page that responds with “Your architect for HDB renovations” is. Keep the copy to what the firm is — interior design and renovation — and let the search term do the matching.
- An ID studio’s Instagram bio: “Interior architecture studio”. The Act reaches derivatives of “architect” in a business designation, so this is exactly the wording to clear with the Board before using. The safe alternative is “interior design studio”.
- An architecture practice’s portfolio reel showing a landmark the founder worked on at a previous firm. Permitted only if the reel states the founder’s actual role and credits the architects involved. Presenting it as the new practice’s project fails para 5(5).
- A waterproofing supplier’s ad: “Recommended by Er. Tan, PE (Civil)”. Para 2(10) prohibits the PE from endorsing the product, so the PE must not agree to it, and the supplier should not run it.
- A corporate-services firm’s homepage: “Your one-stop public accounting partner”. If the firm is not an approved accounting corporation or registered public accountant, this implies authority it does not have under s 56(1). “Accounting, tax and corporate secretarial services” describes the same business lawfully.
- An audit firm’s LinkedIn ad: “Fixed audit fees from $X, lower than the Big Four”. A fee quote is allowed; the comparison is allowed only if substantiated under R115.2. A sweeping comparison with a group of named firms is hard to substantiate and best left out.
What agencies and marketing teams need to know
Three practical points follow from the rules above.
The professional carries the liability for your copy. The architects’ code makes the duty to withdraw improper publicity non-delegable, and both other codes judge the professional by what is published in their name. An agency that writes “Singapore’s best architects” has not taken on the risk; it has handed it to the client. Build a sign-off step where the registered professional approves claims, not only design.
Title checks belong in onboarding. Before writing a single ad for a design, engineering or accounting client, check the public registers: the Board of Architects and Professional Engineers Board registers, and ACRA’s register of public accountants and accounting entities. Then check every profile that carries a title: Google Business Profile, LinkedIn company and staff pages, directory listings and email signatures. Our guide to Google Business Profile optimisation covers where business names and categories surface in search.
Reviews and testimonials need a verifiability check, not a ban. None of the codes bans testimonials, but a review promising a result can fail the unjustified-expectations test when the professional republishes it in an ad. Display platform reviews where they sit, and be selective about lifting them into ad copy. For collecting reviews properly, see how to get Google reviews in Singapore.
The general consumer protection layer still applies on top of all this. A false description of a service is also a trade description problem; see our guide to the Trade Descriptions Act for marketers.
A pre-publication checklist
- Is every protected title — architect and its derivatives, “Ar.”, “Er.”, “Engr.”, “professional engineer”, “public accountant”, “PAC”, “CA (Singapore)” — used only by a person or entity that is registered and current?
- Does any name, tagline, profile category or SEO page imply a service the business is not authorised to supply?
- Can every claim of expertise, size or capability be justified with qualifications, experience and resources?
- Are there any unverifiable superlatives or promises of outcomes?
- Does any ad compare fees or quality with named or identifiable peers?
- Does every portfolio item state the professional’s own role and credit other architects?
- Does any engineer appear endorsing a product?
- Has the registered professional signed off the claims, in writing?
Frequently asked questions
Can an interior design firm call itself an architect in Singapore?
No, unless it is a registered architect or a licensed architectural practice. Section 10(3) of the Architects Act 1991 prohibits using “architect” or its derivatives in a business designation or title, and advertising or holding out as authorised to supply architectural services. The fine is up to $5,000, rising for repeat offenders.
Can unregistered firms do renovation work without an architect?
Yes. Section 13 of the Architects Act allows unregistered people to carry out construction or repair work where no plans need to be submitted to a building authority. That permits the work, not the use of the architect title.
Who may use “Er.” before their name in Singapore?
Only a registered professional engineer. Section 15(4) of the Professional Engineers Act 1991 reserves “professional engineer”, “Engineer”, “Er.” and “Engr.” as titles, and any description implying registration, for registered PEs.
Can a bookkeeping firm advertise accounting services?
Yes. ACRA says general accounting, tax, bookkeeping and advisory work do not need registration as a public accountant. The firm must not hold itself out as a public accountant or use “Public Accounting Corporation” or “PAC” unless approved, under s 56 of the Accountants Act 2004.
Can a professional engineer endorse a product in an advertisement?
No. Paragraph 2(10) of the Schedule to the Professional Engineers (Code of Professional Conduct and Ethics) Rules prohibits a PE from endorsing engineering products or processes in any commercial advertisement.
Can public accountants advertise their fees?
Yes. The ACRA Code does not ban fee advertising, and quoting a lower fee than another accountant is not in itself unethical. Marketing must be honest and truthful, without exaggerated claims, disparaging references or unsubstantiated comparisons, under R115.2.
The takeaway
For architects, engineers and accountants, the most consequential marketing rule is not about the claims in an ad but about the right to the title in it. “Architect”, “Er.” and “public accountant” are protected words, and using them without registration is an offence even when everything else in the copy is true — which is why the businesses most exposed are the adjacent ones: renovation and design firms, engineering contractors and corporate-services providers. Registered professionals then face codes that rule out unverifiable claims, peer comparisons and, for engineers, product endorsements, and that keep them responsible for whatever their agency publishes.
If you market a professional or design practice and want campaigns that build demand without tripping a title rule, that is what our performance marketing team in Singapore does; see our client case studies. Start with our complete guide to performance marketing in Singapore, then digital marketing for professional services and, for B2B lead generation, LinkedIn ads for B2B in Singapore and B2B digital marketing in Singapore.
