If you can't find a particular piece of legislation, it could be because it's a piece of local legislation.

If your Local Act is post-1991:

• Westlaw should have an up-to-date version

If your Act is pre-1991:

• Check the Chronological Table of Local Acts on legislation.gov.uk
• Check the Statute Law (Repeals) Act 2008
• Check the Statute Law (Repeals) Act 2013
• Check the ‘Effect of Legislation’ table, published by TSO in the "Public General Acts Tables and Index", for each year 2009 onwards (these can be found in the bound volumes produced by TSO)

You can also

• Check the Current Law Legislation Citators for each year 2009 onwards, but be warned these aren’t comprehensive (and don’t include the Statute Law (Repeals) Acts 2008 & 2013)
• Run a free-text search on Westlaw’s legislation module for “[Act Title]” /15 (repeal! or amend!) to see if any later legislation has amended your Local Act