To ask the Secretary of State for Health and Social Care, for what reason NHS numbers issued in Northern Ireland are not transferable to England.

There has never been a single National Health Service number system across England, Wales and Northern Ireland. Prior to the introduction of the current 10-digit format NHS number in 1995/96, there were 22 different NHS number formats in existence; one of these was the Northern Ireland NHS number format. The rationalisation that took place introduced the common format we have now. Whilst a common format NHS number is in use there has never been a decision for a single database operating across both authorities.