Choosing an Accountant Who Understands Contracting and IR35

Choosing an accountant who understands contracting and IR35

If you run your business through a limited company, your accountant is one of the most important relationships you have. A general practice accountant can file your accounts and handle Corporation Tax, but contracting has its own quirks: IR35, the off-payroll working rules, VAT flat rate considerations, and the paperwork that HMRC expects if it ever opens an enquiry. Picking a contractor accountant who genuinely understands this world, rather than one who treats you like any other small business client, can save time, stress and money.

This article explains what to look for. It is general education, not personal advice on your own contract or tax position.

Why contracting needs a specialist

IR35 is the common name for the off-payroll working rules, and HMRC maintains dedicated guidance on understanding off-payroll working (IR35). The underlying law sits in ITEPA 2003 (Part 2, Chapter 8, sections 48 to 61, and Part 2, Chapter 10, sections 61K to 61X) alongside the Social Security Contributions (Intermediaries) Regulations 2000, as set out in HMRC's rules for off-payroll working from April 2020.

Since 6 April 2020, medium and large private-sector engagers have generally been responsible for making the status decision, with the fee-payer treated as the employer for Income Tax and Class 1 National Insurance where a contract falls within the rules. Public-sector engagers have operated under equivalent rules since 2017. A contractor accountant should be comfortable explaining how this affects your invoicing, your take-home pay, and your record-keeping, whether you are inside or outside IR35 on a given engagement.

HMRC also groups its material for intermediaries, contractors, clients and agencies (including fee-payer responsibilities) in its off-payroll working collection. A good accountant will refer to this current guidance rather than outdated summaries, because HMRC updates these pages regularly.

What a contractor-focused accountant should offer

Look for a firm that can:

• Explain, in plain terms, how the off-payroll rules apply to your particular type of engagement, without telling you what your status "is" (only the client's Status Determination Statement does that).
• Help you keep the kind of records HMRC expects, such as contracts, correspondence about working practices, and a clear breakdown of company income.
• Support you calmly if HMRC ever opens a compliance check. HMRC's IR35 enquiry guidance confirms that HMRC uses a risk-based approach to decide whether to open an enquiry, and may ask for explanations, income breakdowns and copies of written contracts. If HMRC accepts the position based on what is provided, it closes the enquiry; if it later decides IR35 applies, tax, National Insurance and interest can become due.
• Point you towards specialist advice on contract reviews and IR35 insurance where relevant, rather than guessing at status themselves.

None of this means your accountant determines your IR35 status. That responsibility sits with the end client via the Status Determination Statement, and any CEST result or contract review is best understood as evidence the client has gathered, not a verified outcome.

Questions worth asking a prospective accountant

Before signing up, it is reasonable to ask:

1. How many limited company contractor clients do you currently act for, and across which sectors?
2. How do you help clients prepare for an IR35 enquiry, based on HMRC's current enquiry guidance?
3. Do you keep up with updates to HMRC's off-payroll working pages, and how do you pass changes on to clients?
4. Can you explain the difference between an inside-IR35 and outside-IR35 engagement in terms of payroll and invoicing, without telling me what my own status is?
5. Do you work with, or recommend, specialist IR35 contract reviewers when a client needs one?

A firm that name-checks IR35's formal title of "Off-payroll working", as used in HMRC's director information hub, and can point you to primary GOV.UK sources rather than vague generalisations, is usually a good sign.

A note on due diligence

It is sensible to check that any firm you engage is a properly registered company. Companies House records can confirm basic facts such as incorporation and filing history, but they do not, on their own, establish that a firm has genuine IR35 specialism. Branding alone (a company name containing "contractor accountants", for example) is not proof of expertise; ask for evidence of relevant experience and, ideally, client references from other limited company contractors.

Working with your accountant on status questions

Because IR35 status depends on the actual working practices on the ground, most reputable accountants will be clear that they cannot simply declare your contract "outside IR35". Where a client states that a role is outside IR35, that is the client's claim, evidenced through their SDS, not a fact your accountant or this platform can confirm. Your accountant's role is to help you understand the mechanics, keep good records, and know when to bring in a specialist contract reviewer.

If you are currently searching for work, you can browse outside-IR35 contracts and compare day-rate benchmarks to see how roles in your sector are being advertised. Always read the client's own IR35 position on each listing carefully, and treat it as their statement rather than a guarantee.

This platform does not determine, verify, or warrant IR35 status; the SDS is the client's legal responsibility. Contractors should take their own advice and consider IR35 insurance.