Wanting to set up a special coupon to get customers to sign up for a subscription? You can set up a single-use coupon so that customers first week is discounted only—This can be a great motivator and push for a marketing campaign.
You can set up a coupon code in your shop setting under 'coupons and promos' Take a look at our help guide on setting up a coupon code here: How to set up coupon codes
If you are wanting to set up the coupon code to only be available for their first week you will need to make sure that the coupon is set to 'single-use per customer'
If this campaign is purely for getting people to sign up to a subscription you will also want to make sure your products are set to be available on subscriptions. You will then be able to choose to allow this coupon with subscriptions in the "Allow coupon on subscriptions" dropdown menu.
NOTE: With coupons for subscriptions, you will not be able to offer first subscription free at this stage as Stripe is the payment gateway that's available with subscirption orders and requires a $0.50 minimum value fee so this won't be able to be processed as an order.
Once a customer has added the product to their cart they will be able to enter in the promo code to redeem the coupon for their first week.
For more possible promotion methods, see our help guide What types of promotions I can run for recurring subscritpions.