Checking company industry codes

I have a list of companies, most of which are mapped to SIC (Standardised Industrial Codes). Some of the allocations are inaccurate and need to be checked and/or corrected. Others are missing. In addition, there are some project names that also need to be mapped to SIC. There may also be a need for company size details to be added to the data. The data is in a spreadsheet. The skills and knowledge needed to accomplish this task are: 1 An understanding of SIC codes - what they are and how they are used. You do not need to be an advanced user but \"intermediate\" skills are a requirement 2 Good general knowledge of business and industrial categories - such that you will be able to accurately allocate activities to codes without the need for excessive research 3 Intermediate Excel skills 4 Good web research skills 5 Knowledge of searching databases, including Companies House, would be an advantage.