Subscriber trunk dialling

Subscriber trunk dialling (STD, also known as subscriber toll dialing) is a telephone system allowing subscribers to dial trunk calls without operator assistance. The term was introduced when it first became possible for long-distance calls to be dialled directly, and is now rarely used as calls to any destination can be dialled. This article is about the STD system in the UK.

Subscriber trunk dialling

Subscriber trunk dialling (STD, also known as subscriber toll dialing) is a telephone system allowing subscribers to dial trunk calls without operator assistance. The term was introduced when it first became possible for long-distance calls to be dialled directly, and is now rarely used as calls to any destination can be dialled. This article is about the STD system in the UK.