# reservation/SubscriptionId
#level100 #cur #finops #curfield #curtoanonymise
## Source
- Category: [[Reservation details]]
- [AWS documentation](https://docs.aws.amazon.com/cur/latest/userguide/reservation-columns.html#r-S)
- [[lineItem_LineItemType]]: Fee, RIFee, DiscountedUsage, Refund, Credit, and Usage
## Relevant notes
- This line only applies to [[Reserved Instances]]
## Notes
- This could be connected with a pricing offering, mapping the line with the billing price. In this case it could be useful when special discounts are applied, like [[PPA]]. [[to check]]
- A unique identifier that maps a line item with the associated offer. It is unclear what an offer is!
- The documentation recommends to use [[reservation_ReservationARN]] instead of this field but says that both can be used.
- There can be a subscription id even without a reservation. In this case the [[reservation_ReservationARN]] is empty.