# 2018-05-21 release

# 2018

## 2018-05-21

### Additional updates

| Title                                                                                                                                                                                              | Affected Products  | Breaking change? | Category |
| -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------ | ---------------- | -------- |
| [Products no longer embed lists of SKUs](https://docs.stripe.com/changelog/2018-05-21/products-no-longer-embed-sku-lists.md)                                                                       | Checkout           | Breaking         | api      |
| [Invoice line items now have unique IDs and can’t be used in place of a subscription](https://docs.stripe.com/changelog/2018-05-21/invoice-line-items-have-unique-ids-cannot-use-subscription.md)  | Billing, Invoicing | Breaking         | api      |
| [Coupons, SKUs, customers, products, and plans now limit the valid characters for IDs](https://docs.stripe.com/changelog/2018-05-21/valid-characters-ids-coupons-skus-customers-products-plans.md) | Billing, Invoicing | Breaking         | api      |
| [Subscriptions now default to not defining their trial periods depending on a plan](https://docs.stripe.com/changelog/2018-05-21/subscriptions-default-no-trial-period-plan.md)                    | Billing            | Breaking         | api      |
| [Changing a subscription to a new plan with a trial now extends the trial period](https://docs.stripe.com/changelog/2018-05-21/changing-subscription-new-plan-extends-trial.md)                    | Billing            | Breaking         | api      |