Under the Control of Dogs Act 1986 if you have a dog over 4 months old, you must have a licence for it. You must be aged over 16 years to get the licence. The dog licence is valid for one year from the date of issue and can be purchased at any post office.
If you do not have a licence for your dog, you are liable to a small fine. If you don't pay this fine you can receive a larger fine and/or receive a 3-month prison sentence if convicted.
New rules for identification tags on dogs were introduced in Feb 1999. When a dog is in public the owner must ensure it wears a collar. The collar, or tag or disc attached to it, must include the owner's name and address. You can be fined for owning a dog which does not have an identification tag.