Break Clauses

Tax Planning and Financial

I am about to issue a new AST to tenants. They have been in the house for six months already but their employer has been paying and had signed an initial six month commercial let contract. The occupiers now wish to become the 'tenants' and so I am issuing a new AST. However, they may not want to stay for the full 6 months as they hope to find a larger property when their families come over to the UK from the Phillipines. I am happy with this but am unsure about the position and wording of a 'break clause'. Can you make suggestions please.

Thank you.