How to send data from one form to another in preference to data entered previously

I have created two forms with data being transferred from the first form to the second form.I also want the form to be able to be finished later. However with this enabled the 2nd form is taking the data from the last time it was completed rather than from the date entered by the first form.

Is there a way round this if I keep the option to complete form later?

If you're using the continue forms later (also known as auto-fill feature) then the data will be saved in the web browser so if the data is previously passed from the first form then this data will be saved in the second one. 

Now, what you could do is to use the session method, the save form and continue later feature, this way the data will be saved by session and not in the web browser's cache, this will also help your users to fill our the form in different devices. 

Since you have already the two forms needed to apply this feature you will only need to add the "session" variable to the link you already have for your second form, please check this guide to get more  details about it: How-to-Save-Forms-and-Continue-Later

But do note that each time the form data is updated in the second form this modification will be saved and displayed the next time that the form is opened. 

Do let us know if you have any question.