Just browsing websites to see differants between the staffordshire bull terrier & american staffordshire terrier .
I saw in Ireland (not sure if the websites are RIRL/NI so just guessing) that some of the site mention importing AST & breeding? so i thinking its Republic of Ireland & not NI as it apart of GB. that its  illegal to own american staffordshire terrier in GB & NI but not in the RIRL even if the dogs are registered with RIRL?
just like to know are Regiserted American staffordshire terriers ban in GB NI please

HOPE this is useful. try looking on DIRECTGOV just copied & paste this small piece off it hope it helps.
What is a 'type' of banned dog?
Whether your dog is a banned type depends on what it looks like, rather than its breed or name
A dog type is not a breed. Whether your dog is a banned type depends on what it looks like, rather than its breed or name.

If your dog matches many of the characteristics of a Pit Bull Terrier, it may be a banned type. This is because dogs with these characteristics are more likely than other dogs to cause severe harm if they attack.

It won't matter what type or breed a dog's parents were. (Cross-bred and mongrel dogs can have the characteristics of a Pit Bull Terrier.)
Pit Bull type dogs
Pit Bull types may include the following dog breeds:

*American Staffordshire Terriers
*Irish Staffordshire Terriers
*Irish Blue or Red Nose
Some kinds of American Bulldogs have been found to be Pit Bull types.

Staffordshire Bull Terriers
Staffordshire Bull Terriers are not listed in the Dangerous Dogs Act 1991. You are allowed to own this breed of dog.

American Staffordshire Terriers ARE a recognised breed by the relevant Kennel Clubs of (to name two) Australia and the US, though not in the UK.

They are unfortunately deemed to be of 'type' (i.e. pitbull 'type') where breed specific legislation and certain other legislative laws exist.

Amstaffs are an FCI recognised breed. The origins of the name is due to the AKC not wanting to use the name American Pitbull Terrier when adding them to their registry. They registered existing UKC registered pitbulls and called them Staffordshire Terriers in 1936. The standard was based on a pitbull called Colby's Primo. UKC and ADBA were registering dogs as pitbulls before the AKC did this in 1898 and 1909 respectively. The AKC changed the name in the 1970's to American Staffordshire Terrier, to avoid confusion with the Staffordshire Bull Terrier which the AKC added to their registry.