If you get the error message #502 – fatal: Authorisation Failure when filing to Companies House, it means that one of the following entries is incorrect or missing. Check all the details carefully and re-enter them where possible. Delete any spaces appearing at the end of an entry.

• Company type – make sure the correct type is selected:
  • EW – England and Wales company
  • SC – Scottish company
  • NI – Northern Ireland company
  • R – Northern Ireland company registered before the partition of Ireland in 1922
  • OC – other England and Wales company (only used for LLP cases in liquidation)
  • SO – other Scotland company (only used for LLP cases in liquidation)
  • NC – other Northern Ireland company (only used for LLP cases in liquidation).
• Company registration number – if this is wrong, change it on the accounts.
• Company Authentication Code – a six-character alphanumeric code which is specific to the company you're filing. Please note this is case sensitive and is usually expected to be capital letters. 
• Email address – this needs to match the one you used to register for the Presenter Identifier and Presenter Authentication Code.
• Presenter Identifier and Presenter Authentication Code – these are both provided by Companies House and aren't the same details as you use to log in to their website. The Presenter ID is 11 digits long and starts with 000 and ends in 000, this contains a mixture of numbers and letters.  If you don't have these yet, fill in the application form and email it to Companies House. Please note that the Presenter Code is case sensitive and is usually expected to be capital letters.