What is the 'Raise Subscription' function?

The Raise Subscriptions function allows you to generate pending transactions for Subscriptions, Renewal Invitations and Parent Subscriptions where a member subscription is about to/or has expired. Raise Subscriptions can be accessed under Administration / Accounting /  Raise Subscriptions.

Nothing is updated by this process. It is creating a list of recommended renewals that are passed forward to Pending Transactions for further review and subsequent processing.

On step 1 of this multi-step process you select the types of subscriptions and members you want to raise subscriptions for. You can specify one Subscription Group, one Subscription Code, multiple Subscription Frequency, one member (by entering a member code, defaults to all Members), one or all Branches (if enabled), and multiple Payment Methods. Click the List Subscription Codes button to see the marching subscription codes.
Note: the default behaviour, if you do not enter anything on this page is to raise ALL subscriptions.

Step 2 lists all of the matching subscription codes, you can exclude an individual code by unchecking the checkbox next to it. Click the Accept Subscription Codes button to move forward.

Step 3. Enter a date range. Any Member Subscription that has a subscription code that is in the list of accepted subscription codes AND has Subscribed Until Date that is less than or equal to the ‘To’ date and greater than or equal to the ‘From’ date will be included in the raise subscription process. Click the Prepare button to move forward. 
Note: The members subscription will be raised until the subscribed until date is BEYOND the To date entered. If the members current subscribed until date is more that one period of the subscription before the to date (and after the From date) the member subscription will be raised more than once.

Step 4 gives you a summary of the number of member subscriptions to be raised, including totals for each type. If the numbers appear to be incorrect, you can cancel from this page and rectify any issues with the member data. Click the Generate button to move forward and create pending transactions

Step 5 confirms the number of pending transactions created. You now need to process the pending transactions.

See also How do I process pending transactions?