While the UK isn't a litigious society, it does make sense to know your legal rights and responsibilities when lending a ladder (or any other equipment) to someone else.  There are slight differences in the way this works for professional users and for people who are lending a ladder to a friend or neighbours, but in both instances the lender can be held liable for any accidents occurring as a result of using the ladder under certain circumstances.

On a building site contractors may ask to use your ladder if the ones they have aren't tall enough or aren't the best type for the job.  If you agree to lend a ladder to another professional user you then take on the responsibility of their employer to ensure the ladder is safe to use, and if they have an accident while using the ladder that is a direct result of a fault in the equipment then you are indeed liable for that injury.

You can take some steps to mitigate against prosecution and we recommend that you do take precautions, for your own safety as well as the safety of the person borrowing the ladder.  Perform a full safety check of the ladder before you lend it and keep a record of this; ideally you should get the person borrowing the ladder to co-sign your safety check sheet, as this is proof that the ladder was safe to use and that the person using it agreed that it was fit for purpose.  It is then their responsibility to ensure they use the ladder safely and protects you from any potential lawsuit regarding the safety and integrity of the equipment.  You should have ladder inspection tags or stickers on your professional equipment, and this is a good sign that the ladder has been recently checked and passed.

Before lending a ladder to another contractor ensure you have agreed this arrangement with the manager of the contractors (this may be the same person).  This ensures that all parties are aware of the arrangement and of the signed checklist.  If you are concerned that the person borrowing the ladder is using it incorrectly or has not received proper ladder training you should not lend the ladder, and if they have already set it up badly it's best to say something at this stage, rather than risk an accident and the potential for legal wrangling if the other party decides to pursue this (fruitless) route.

If you are lending a ladder to a friend or neighbour you can be held liable for an accident they have while using it, but only if they can prove that you knew the ladder was faulty when you lent it.  For this reason it is wise to conduct a safety check of the ladder in the presence of the person borrowing it and ask them to sign something to say that they are happy with the condition of the ladder.  Generally speaking, you wouldn't knowingly lend a faulty ladder to someone you like, so it's unlikely that you would get into any trouble with privately lending a ladder, but it is better to be safe than sorry.  If you want to be really sure, offer to help your friend or neighbour with the job and you can be there to steady the ladder and ensure it is being used properly.

If you are asked to lend your ladder to anyone, under any circumstances, do make sure you have written agreement that the ladder is safe to use, and that the person borrowing it will not hold you personally responsible for any accident or injury that occurs as a result of using it.