This page covers ICAEW only. The requirements that apply to every UK practice website are on what UK rules require of a practice website.
Plenty of firms assume the description is available the moment one qualified person joins. That assumption trips people up more than anything else on this site, so this page goes past the summary and into the mechanics ICAEW actually applies.
What counts as an eligible "member firm"
The exact test sits in ICAEW's regulations on the use of the description, and it turns on voting control rather than headcount. Practise alone, as an ICAEW member, and there is no separate ownership test to clear. a partnership or LLP qualifies only if more than half the rights to vote on matters of substance are held by Chartered Accountants or other qualifying member firms, and a company qualifies only if more than half its directors, more than half the nominal value of its voting shares, and more than half the value of its voting and non-voting shares together, are held the same way.
In other words, a firm with one chartered partner and three non-chartered partners does not automatically qualify just because one of them is chartered. What matters is whether that one partner, or a combination of chartered principals and other qualifying firms, actually controls the vote.
If not every partner or director is a Chartered Accountant
The regulations do not require every principal to be chartered. A partner, member or director who is not a Chartered Accountant, or another qualifying member firm, can still sit inside an eligible firm provided they hold one of several recognised statuses instead, such as affiliate status with ICAEW, registration for audit or local audit work, accreditation for legal services work, or a licence under ICAEW's Designated Professional Body or Licensed Practice arrangements.
If that requirement briefly falls out of step, for example after a new partner joins, the regulations give the firm up to three months to put it right, provided it can demonstrate it intends to meet the requirement, rather than losing the description the moment the position changes.
Applying for a dispensation if the ownership test is not met
Falling short of that test is not the end of the road. A firm can put a case to the ICAEW Regulatory Board, which has the discretion to grant permission to use the description anyway, wholly or in part, on whatever terms it sets. That permission can later be withdrawn for cause, and a firm unhappy with the Board's decision has 14 days to ask for it to be looked at again.
This route exists precisely for firms whose structure does not fit the standard ownership test, so it is worth reading if your firm has an unusual mix of principals rather than assuming the description is simply out of reach.
What this page does not repeat
Money laundering supervision, the company details a limited company site has to show, and the privacy and cookie rules around a contact form apply to an ICAEW firm exactly as they apply to any other UK practice. They are covered once, in full, on the hub page, rather than repeated here.