When you assign a lease, there are three sets of professional advisers involved: yours, the new tenant's and the landlord's.
Under the terms of the lease, you will usually be responsible for paying for both your and the landlord's advisers. Of course, you can negotiate with the new tenant how these costs will be shared between you.
If the lease is attractive, the new tenant will usually pay you a premium: for example, if the rent is below market rent, or if the new tenant will also be getting goodwill attached to the business for which you have been using the premises. But you might have to pay the new tenant to take on the lease: for example, if the rent is high or the premises are dilapidated.
You will also need to cover the costs of finding the new tenant, such as the commission charged by any agents you use, and your own relocation costs.
