Diff. between Change in Terms of lease & an Authorization letter?

[Cody Barrett]

Hey everyone!

New landlord here.. I am curious if there is a difference between an Authorization letter and a Change in Terms of Lease Addendum.  If there is a difference then I assume that it is situation specific?  

For EX: If the tenant wanted sole access to the deck upstairs but the lease does not state that he receives sole access with his rent rate, would I use the Change in Terms of Lease Addendum stating that I approve of him having sole access to the deck upstairs? OR would it just be a simple authorization letter granting him permission to have sole access to the deck?  I feel like I am splitting hairs here but I just want things to be documented correctly.  

EX # 2: 

Tenant has a Sole Prop business where he uses the address for quotes on landscaping work since he doesn't have a stand alone store.  He is a tree arborist.  (He keeps the lawn in great shape and is an awesome tenant..)  I inherited him (7 Year tenant but 1st month with me)

When I recently purchased the property and when I was going over my lease he stopped me after I stated that the premise is to be used for residential purposes only.  I am happy that he notified me of this rather than being sneaky... SO for this situation, if I decide that it is ok, would it be an authorization letter granting permission to have his business address be the unit's address (technically running a business out of the unit)?  Or would I use a change in terms of lease addendum?  

Sorry for the silly question.. But thank you so much for reading and helping out!! : )