Having your jewellery and other precious belongings valued is vital to making sure you are adequately covered by your insurance policy. Without an accurate, up to date valuation you run the risk of being under insured in the event of loss or theft. Many insurance companies even insist that you have items over a certain value specified individually on your policy and regularly valued to ensure the limits are adequate.
Guild valuations provide you with proof of ownership which your insurance company may require in the event of a claim. Without this proof you may find that replacement is based on an item of "average" quality rather than what you have actually lost. Having your jewellery valued every 2-3 years will ensure any information about market values is up to date.