All of my silver work is made in sterling silver, occasionally with elements of gold. If an individual silver item is over 7.78 grams then it will be hallmarked accordingly as required in the UK. If an item weighs less than that then it does not need to be hallmarked.
This is the legal notice. It contains some interesting information about hallmarking.
My makers mark is registered with the London Assay Office at Goldsmith's Hall which is where they would assay and hallmark my work.