Thatcham is a town in Berkshire, England located 3 miles (5km) east of Newbury and 15 miles (24km) west of Reading. It covers approximately 8.75 square miles (23 km²) and has a population of 23,000 people (2003). This number has grown rapidly over the last few decades from 5,000 in 1951 and 7,500 in 1961.

An independent department of the insurance industry that tests and approves alarms and immobilisers to give car owners security and a discount on insurance premiums.

An approval standard for automotive security.