Late Rent Question on Process

[James Edwards]

How does everyone handle late rent, appx twice what the late day is considered?

Renter has been overall good and keeps the house up, but has been rather needy at times. 

Tenant agreement spells out a late fee penalty. 

Would a simple text to see about rent be good? While I believe following the agreement is good,  I'd really hate to get into the late fee aspect because it can start getting tit for tat. 

Thoughts?