addendum

Other

hi my letting agent has informed me that tenant has changed rent payment date from 28th to 1st month. i told agent that tenant can not unilateraly change ast as it is binding document and would need my agreement to change , could/should an addendum be put in place to cover change , signed by both landlord and tenant or would new ast need to be drawn up at tenants expense . tenant/agent have paid to me extra 4 days rent to cover change added to last rental payment, is there anything i should be aware of or pitfalls . tenant wants to change as her finances have changed and would be constantly late paying rent, regards gregsta