If the company is no longer required would suggest that you apply to Companies House[CH] to have the company removed from the register. You will need to apply on a form DS01 and it will cost £10. If you are VAT registered and have a PAYE scheme I would suggest that you deregister in order that they do not object, even if you owe money. You will need to write to all known Creditors, inc CH, and I would suggest that you get a proof of posting from the post office for each letter. When CH receive this they will advertise it in the London Gazette and if no one objects within 100 da