A family of Microsoft word processing software products for creating web, email, and print documents.
I'd suggest adding AutoText entries to your "single" template, and using a macro to drop them into the current document when you make a selection in the dropdown for the client.
For each part of the document that needs to change per client, you may need as many AutoText entries as there are clients, or fewer if some of the clients get the same text in that part. You'll want to establish a logic naming convention for the entries, so the macro can select the correct entry for a given part and a given client.
The kind of macro you need depends on which type of controls (content controls or legacy form fields) you intend to use. That choice in turn depends on whether you need to type or paste information into any places in the document that aren't within a control or field.
- If you use content controls, the macro should be named Document_ContentControlOnExit and stored in the ThisDocument module of the template. That causes the macro to be called automatically whenever the cursor exits from any content control. The code that goes inside the macro first checks that the control being exited is the client dropdown. If that's OK, then it uses the value of the dropdown to choose the AutoText entries to insert at bookmarks in the body of the document.
- If you use legacy form fields, the dropdown field has a place in its Properties dialog where you can specify the name of a macro to run when the cursor exits from that specific field. As for the content controls, the macro (which belongs in an ordinary module) uses the value of the dropdown to choose the AutoText entries to insert at bookmarks in the body of the document.
If you're unfamiliar with macro coding or just want a sample to work from, send an email to me at the address you'll find at https://jay-freedman.info/contact/contact.htm .