Companies House has announced that from 25 March 2020, companies can apply for a three-month extension for filing their accounts. Those citing issues around the coronavirus as the reason they are unable to file on time will be automatically and immediately granted an extension. Applications can be made through an online portal at https://beta.companieshouse.gov.uk/extensions
Full guidance on how to apply can be found at https://www.gov.uk/guidance/apply-for-more-time-to-file-your-companys-accounts