Late registrations for employment related securities.
If you miss the registration deadline for an employment-related securities scheme, you must contact HMRC in writing to explain the reason for the delay. This applies to Company Share Option Plans, Save As You Earn schemes, Share Incentive Plans, and Enterprise Management Incentives notifications. You can submit your explanation by email to shareschemes@hmrc.gov.uk or by post to HMRC, BX9 1AU. If your excuse is accepted, HMRC will provide instructions on how to register or file your return late, though late filing penalties may still apply.
Source: https://www.gov.uk/guidance/late-registrations-for-employment-related-securities. Summarised automatically from the official source — general information, not advice.