Ok firstly, we dont have forklift "licences" in the UK, they are cerificates of training, the layout of all certificates is broadly the same but obviously different training organisations have slightly different formats & logo's.

If you do not have your actual certificate and was trained by Linde you should be able to get a duplicate cerificate from them, they may charge a small admin fee for this.

If you undertook an accredited course then the certificate should be valid anywhere subject to the new employers policy, for example some employers will want to get you re-tested again as per their policy on taking operators from other companies, but at least you have proof of training which means you would only need a re-test and not another full course, hope this helps.