Beta This part of GOV.UK is being rebuilt – find out what this means

HMRC internal manual

Senior Accounting Officer Guidance

HM Revenue & Customs
, see all updates

How HMRC manages qualifying companies

The Senior Accounting Officer (SAO) provisions do not apply to all companies. They only apply to ‘qualifying companies’ (see SAOG11000 onwards) which can include those managed by Large Business or Wealthy and Mid-sized Business Compliance directorate.

For the largest and most complex businesses HMRCs approach is to engage directly through a Customer Relationship Manager (CRM). If your business has been allocated a CRM you should follow the guidance for businesses managed by Large Business.

Businesses defined by HMRC as mid-sized businesses do not have a CRM allocated to them.

For HMRC operational purposes a mid-sized business is defined as having either or both a:

  • UK turnover of £10 million or above, and/or
  • Minimum of 20 employees.

For businesses which are qualifying for SAO (see SAOG11000 onwards) and which fall into this definition, but which do not have an allocated CRM you should follow the guidance in this manual for businesses managed by the Mid-sized Business Customer Engagement Team (CET) or a Caseworker.

The address for most mid-sized business customers to send notifications, certificates or other correspondence is:

MSB Customer Engagement Team (SAO)
Floor 17 (West)
Euston Tower
286 Euston Road

The email address is

The address for notifications, certificates or other correspondence relating to mid-sized business oil and gas customers is:

Alasdair Downie
MSB Oil and Gas Team
Cotton House
7 Cochrane Street
G1 1GY

For information about when you should write to HMRC and what details to provide, see