There are various cases where a domain name may not be transferable to another Registrar. This could happen in the following circumstances:
Domain name is less than 60 days old: If the domain name you are trying to Transfer was registered less than 60 days ago, the request will get rejected by the Registry itself.
Domain name has been Transferred less than 60 days ago: A domain name can not be transferred to another Registrar within 60 days of a previous Transfer.
A domain name can not be transferred from Registrar B to Registrar C, if it has been transferred to Registrar B from Registrar A within the last 60 days.Note
An exception to this rule is, the Transfer back to the previous Registrar in cases where both Registrars so agree and/or where a decision in the dispute resolution process so directs.
Theft Protection / Lock / Suspension has been applied on your domain name: If Theft Protection / Lock / Suspension has been applied on your domain name at the Current Registrar, then a Transfer for that domain name to another Registrar will not be allowed. You will first have to disable Theft Protection / Lock / Suspension for the domain name and then proceed with a Transfer.
Disabling Theft Protection / Lock / SuspensionAdditional Information
How to Disable Theft Protection / Lock from a domain name?
How to Unsuspend your domain name?
Privacy Protection has been enabled on your domain name: If you have enabled Privacy Protection for your domain name, then you need to disable it, before trying to transfer it.
Domain name is in the Redemption Grace Period or in the Pending Delete status: If the domain name is in either of these statuses, it can not be transferred.
Domain Name Extension Specific Conditions
Only .CO, .COM.CO, .NET.CO, .NOM.CO domain names can be transferred.
A .UK domain name can be renewed upto 90 days after its Expiry, post which the domain name would be automatically deleted by the .UK Registry. There is no restriction on transferring a .UK domain name during this period. However, you need to ensure that there is sufficient time prior to Deletion, so that the domain name can be renewed with the new Registrar once the Transfer process gets completed successfully. This is because Transfer of a .UK domain name does not include one year Renewal.
Apart from this, none of conditions listed above apply to the Transfer of a .UK domain name. This is because the .UK Registry does not support any Theft Protection / Lock / Suspension / Privacy Protection / 60 day Registration or Transfer Lock and there is no concept of a Redemption Grace Period in case of a .UK domain name.