Dear Mr. Maurice Moretti , 

Regarding to subscriptions and their management, As you know there are important basic things that you must have to ensure the success of the operation, It is as follows:

Assuming we work in a sport gym under the name (Golden gym), you must do the following: 

(In general)https://www.youtube.com/watch?v=RjbHhfCQPMc&t=287s

**From accounting app> configuration> chart of accounts> created some accounts like:

- Revenue from swimming pool (for example) 

-Unearned revenue from swimming pool (for example)

**From Sales app> Product > create new Product with name (swimming pool) with the required specifications, as in the illustration image No. 1. Note that in the attached pictures, I defined the product and allowed it to be in the form of a monthly subscription,  also I have put in other details of the product like tax, price and cost  and it is only for sale, More importantly, I linked the product to a specific type of Invoice period and Duration and Deferred Revenue Type

** and as you know, you can through the subscriptions app

> Configuration> create many Subscription Templates hen when creating a new product, you link the product to the type of subscription required.

For your question specifically:

You cannot create a SO amounting to  120$ to indicate  the whole year's fee and then split it into 4 quarterly bills even if the billing policy  is based on the quantity delivered!

So I recommend that you submit an annual quote by adding a note that billing will be on a quarterly basis. Then make a quarterly subscription automatically renewed(by Invoice period & Duration)  . In the event that the customer stops the subscription, you will not have to cancel 3 bills. This will not affect financial collection. Finally you can add any notes on your subscription invoice by 

1. Subscription Templates - Terms and conditions

  

I hope my answer is clear 

best regards,