By law all limited companies are required to draw company accounts that include (a) Profit and Loss Account, (b) Balance Sheet along with the Directors Report signed by one of the directors of the company and (c) Auditors Report signed by an Auditor.
This report, also known as "Annual Report", must be filed with the Companies House within the stipulated period.
Company's first Annual Report must be filed with the Registrar within 22 months of the date of incorporation for private companies and 19 months for public companies or 3 months from the accounting reference date, whichever is longer.
Subsequent years accounts must be submitted within the stipulated period failing which automatic civil penalty depending on the delay and the nature of the company will be levied. The filing dates for accounts will be reduced from 10 months to 9 months for private companies and from 7 months to 6 months for PLCs.
Further information is available on FAQ section of Companies House website:
http://www.companieshouse.gov.uk/infoAndGuide/faq/accountsAndReports.shtml