tion UPN in this field; leave it blank instead. 28 2.4 UPN unknown reason This item is optional and is included to assist local authorities in informing DfE why a UPN is missing. The UPN unknown reason codes are listed below: Code Description UN1 Child is not of school age and is not yet assigned a UPN. UN2 Child has never attended a maintained school in England and has not been assigned a UPN. UN3 Child is educated outside of England and has not been assigned a UPN. UN4 Child is newly in need (one week before the end of the collection period) and the UPN is not yet known at the time of the children in need census return. UN5 Sources collating UPNs reflect discrepancy/ies for the child’s name and/or surname and/or date of birth therefore prevent reliable matching (for example duplicated UPN). UN6 Child is not looked after and the local authority is unable to obtain the UPN. UN7 Child referred but no further action taken. 2.5 Date of birth The date of birth should be recorded using the format specified in date fields of the general notes section. If the exact date of birth is not known, record an approximate date of birth based on the child’s estimated age at date of referral. This field will be blank for unborn children. If an unborn child is subsequently born in the period of need, then the date of birth should be entered and the expected date of birth should be deleted. 2.6 Expected date of birth Record the expected date of birth (due date) for a child who is unborn at the time of referral and who remains unborn at 31 March or when the case is closed. The expected date of birth should be recorded using the format specified in date fields of the general notes section. If a child is stillborn, or the mother suffers a miscarriage (including a chemical pregnancy) or a pha