Looking on the internet deeply has found these results:

I will get back to you shortly with the required documents. is the most popular phrase on the web.

I will get back to you shortly with required documents. 17,340,000 results on the web	I will get back to you shortly with the required documents. 114,900,000 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
To me it is something from theatre, and I will get back to that a little bit later. We'll get back to you shortly. Okay, and I will get back to work. I will get back to you on the detail when I have had a chance to study the matter. Well, I will get back to the outer layer... I will get back to you on all of this later. I will get back to making your wedding absolutely perfect. Let me check the details and I will get back to you with the results of my enquiries.	To me it is something from theatre, and I will get back to that a little bit later. Well, I will get back to the outer layer... We'll get back to you shortly. Let me check the details and I will get back to you with the results of my enquiries. Okay, and I will get back to work. I will get back to you on the detail when I have had a chance to study the matter. I will get back to making your wedding absolutely perfect. I will get back to you on all of this later.

I will get back to you shortly with required documents.

17,340,000 results on the web

I will get back to you shortly with the required documents.

114,900,000 results on the web

More popular!

To me it is something from theatre, and I will get back to that a little bit later.
We'll get back to you shortly.
Okay, and I will get back to work.
I will get back to you on the detail when I have had a chance to study the matter.
Well, I will get back to the outer layer...
I will get back to you on all of this later.
I will get back to making your wedding absolutely perfect.
Let me check the details and I will get back to you with the results of my enquiries.

To me it is something from theatre, and I will get back to that a little bit later.
Well, I will get back to the outer layer...
We'll get back to you shortly.
Let me check the details and I will get back to you with the results of my enquiries.
Okay, and I will get back to work.
I will get back to you on the detail when I have had a chance to study the matter.
I will get back to making your wedding absolutely perfect.
I will get back to you on all of this later.