Dang I’ll be in Mexico that week.Please keep me in the loop anyhow.

If my schedule fills up before you're able to book your appointment, send me an email requesting an invoice and I will do my best to send it to you.I look forward to talking with you again soon!

Dang @Joel Fine, I feel like you made some really good points.

Take pictures before you repair, save the invoice for the repair and rekey.

Now he could invoice those items in the background and just give you the final total, but if asked for the breakdown and he gives you that you can't beat him up for how he arrived at his number...

If I was not replacing the item with the same item, I would not charge the tenant, since there will not be an invoice to substantiate the charge.  

However, if you have a separate contract for the storage unit rental and it's not on the premises of the residential rental unit, then it may fall under storage unit rental laws.It's paramount that you invoice in a timely manner whenever a tenant owes you for something.

Send her the invoice for reasonable repairs with a payment plan option?

I'll let you know what I think.I use Quickbooks for invoicing rent, and the desktop version just increased ACH transfers from $1 to $3 per transaction. 

But, dang, it's a pain to get there from here.