Matching common record to CRM

Hi Guys,

I have a problem that I need to solve to sign up new clients to FreeAgent.
I’ve been directed here as FreeAgent say this is the place where someone
here might know the answer.

Firstly, let me say I’m not a developer,so am not particularly technical.
However, here’s my problem and I’d be really grateful for advice.

Here’s the summary of what I’m trying to achieve for both my own account
and that of one of my clients.I am trying to take information from FA
(triggered upon production of an invoice) to take the net value and use it
to update a CRM (part of our marketing automation software. SharpSpring). I
am doing this via the API integration to Zapier.

The problem I am having is that none of the fields that I am able extract
from FA identify the customer/client. When we setup a new client in
SharpSpring it uses Zapier to setup a new client in FreeAgent. However,
when FA bills the client, we are unable to pass this information back to
SharpSpring, as FA does not seem to pass a unique client identifier back to
Please can you help me resolve this as, in this case, it negates the value
of FreeAgent’s Zapier integration.
Many, many thanks