If your membership program is an Annual Dues Based program, this is not currently possible with Altru's current functionality. If this is something you'd like to see added to Altru, please vote for our idea here: Ability to use Membership installments to pay over time.

In the meantime, your organization can enter a $0 or comped membership and add a pledge directed toward a membership fund in your fundraising hierarchy to accomplish this. On the pledge record, you can schedule the installments and select for them to be paid automatically. 

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Your organization can also set up a Recurring/Sustaining Membership Program in Altru. A Sustaining Membership Program will be a separate membership program from your Annual Dues Based Program. The Sustaining Membership Program is tied to a membership recurring gift that is charged on a regular basis. The member continues to be active as long as they are making the regular payments. There are no expiration dates and no renewals. For more information on setting up a Recurring/Sustaining Membership Program, see our Guide here: How to Set Up a Recurring or Lifetime Membership Program