Transfer ID from Stateless form to Stateful form

Transfer ID from Stateless form to Stateful form

Hi, 

I have 2 forms:
Page1 (Stateless) 
MasterForm (Stateful) 

Scenario:
In "Page1" I have fields like Names,Phone etc and a Button "Next". When I click Next,
it will show "MasterForm" and it has other fields for user to fill in and a "Submit" Button. 

Problem faced: 
When I click "Next" in Page1 it generates in report as ID "1234", and when I click "Submit" in MasterForm it 
generates ID as "5678".
Which is not right as the data generated in "MasterForm" should be synced with data generated in "Page1"

Desired Outcome: 
I want data from user keyed in Page1 to be under the same ID number as user data from MasterForm and by that, 
I need to reference to Page1 data ID 

Restriction: 
I do not want to use URL link to transfer the ID number. 

Question: 
Is there an option for me to transfer ID between forms by "Get Set" Functions? Any other solutions are welcome too


Thanks in advance!