Things to give your accountant & how to find them.

| 20th September 2013

After you’ve agreed to use a certified accountant, there are various administrative steps that need to be done to let HMRC know, and so that the accountant can do their job to the best of their ability.

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We need to get various codes and reference numbers from you, and when we ask for them, we sometimes rush over the explanation of what everything is, and how to get it.

To alleviate this, we’ve decided to put together a handy glossary of the commonly used terms, what they mean and how/where to get them. It’s been split into Company/Individual/General so that you can skip to the most relevant part for you.


SA-1/CWF1 – Forms used to inform HMRC that you now have to submit a tax return, for whatever reason. The CWF1 form is used for people who have started as a sole-trader/self-employed. The SA-1 covers any other reason you may have to submit a tax return. The most common are –

i)                    you became a company director

ii)                   your income is over £100,000 per year

iii)                 you have rental property income

iv)                 you have Capital Gains Tax to pay

Before using these forms, you will need a national insurance number, or NINO – see below.

64-8 – Form used to authorise the accountant to talk to HMRC about your tax affairs on your behalf. An alternative method that we can use is to request an authorisation code to be sent to your address. This takes less time overall, however it relies on you to receive it and send it to us (it has an expiry date). Generally, your accountant will want to have a completed paper form on record anyway.

Personal Tax

UTR – Unique Taxpayer Reference. This is a 10 digit code used by HMRC to identify you as a self-assessment tax-payer. It will automatically be issued once you have submitted an SA-1 or CWF1 form.

If you do not know what it is, you will be able to find it on most correspondence from HMRC. If that is not possible, then you will need to phone up the self-assessment helpline on 0300 200 3310. They will ask you to confirm your details (name, date of birth, address, National Insurance Number etc).

NINO – National Insurance Number. 9-character alpha-numeric code used to identify you through employment. Comes in the format AB 12 34 56 C.

If you want to work in the UK, you need a NINO. If you were born and resident in the UK, you will have automatically been issued with one, but if not, you will need to apply for one.

To do this, you need to make an appointment for an interview with Jobcentre Plus (0845 600 0643). Full details can be found here. In our experience, the whole procedure (from initial application to receiving the NINO) generally takes around 6 weeks, though that may differ. 


If you are the director of a limited company, you have various statutory obligations (for our FAQ, please click here). The two main organisations are HMRC and Companies House, who each have their own codes and references.

Companies House

Company Number – Eight-digit number used to identify your company. It will be found on the company formation documents, or by using the Companies House website and typing in your company name.

Companies House Authentication Code. This one is a bit trickier to find. It is a six-character alpha-numeric code which you will receive when you formed the company. If you use an online formation agent, it should be provided to you in the email (along with the company documents). Alternatively, you will receive a letter from Companies House containing the code, normally within a week of the formation.

If you cannot find the code through either method above, then a replacement can be requested from the Companies House website, listed above. You will need to sign into a web-filing account, and click on the ‘request an authentication code’ link.

Companies House will issue the code to the registered office address of the company, so if you are using a registered office service, then make sure that it arrives or is forwarded.


Company UTR – similar to the personal UTR explained in the Personal Tax section, however with an important difference. There is a 10-digit code; however it is preceded by a three-digit tax office reference. This number will depend on where the company address is. It is used to pay your Corporation Tax.

This code is sent by letter when the company is formed. As above, with the Companies House Authentication Code, it is sent to the registered office address, so make sure you have access to this.

If you have lost it/to find out what your tax office reference number is, you can use this link, and enter your town or postcode. This will give you the details of your local tax office, which will be able to help you with the Company UTR.

VAT Registration Number. If you register to submit VAT returns, you will be issued with a VAT registration number, in the format 123 4567 89. This is needed to submit VAT returns, and also is used as a reference to pay any VAT due to HMRC.

You will receive a registration certificate from HMRC containing this number. If you lose this, or have no way of finding out what it is, then call the VAT Helpline 0300 200 3700.

PAYE Reference Number/Accounts Office Reference Number

If you register for PAYE, there are two reference numbers issued to you – the PAYE Reference number, and the Accounts Office Reference Number.

PAYE Reference Number – This is the number that you see on your payslips. It will be in the format 123 / AB45678.

Accounts Office Reference Number The number used to pay your PAYE tax liabilities. In the format 123AB0045678.

 The contact number for the PAYE Helpline is 0300 200 3200.

Other Advice

–          Once your accountant is authorised, they have access to dedicated phone-lines, which are quicker than the general helplines, so it is worth completing the authorisation process as quickly as possible.

–          Keep a record of all communication you have with HMRC – dates, times and the names of the people you spoke to. In the event that something goes wrong, it may be easier to prove that you are not at fault.

–          As an alternative to calling HMRC (if it is not urgent), you can contact them by post. Their processing time will vary from department to department, and it generally takes a couple of weeks from them posting a reply to you receiving it, but you have the added benefit of a paper-trail. The general postal addresses are listed below (and are also on the HMRC website).

For Personal Tax:

HM Revenue & Customs
Self Assessment
PO Box 4000
CF14 8HR

For Companies – your tax office (please see link above).

For VAT – You can email HMRC with your enquiries


HM Revenue & Customs
VAT Written Enquiries Team
4th Floor, Alexander House
Victoria Avenue
SS99 1BD


Customer Operations Employer Office
Chillingham House
Benton Park View
Newcastle Upon Tyne
NE98 1ZZ

If, after all that, you still haven’t found what you’re looking for, please contact us directly or use our ask-an-accountant service!

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