What is the maximum length for a payment id field?

Payments + Shipping & Fulfilment

Topic summary

  • Main issue: Clarification requested on the maximum length and allowed characters for the payment id field in Shopify’s Payments API.

  • Context: The requester cites Shopify documentation where id is defined only as a String, used as the idempotency key (requests with the same ID are treated as identical), and must be surfaced to merchants to correlate Shopify orders with partner-managed payments.

  • Gap: The docs do not specify any constraints such as maximum length or permitted special characters for id.

  • Ask: Provide explicit specifications for id length limits and character set/format requirements for payment id.

  • Status: No responses or decisions yet; the question remains open and awaits an official specification or documentation update.

  • Materials: Link to the relevant Shopify documentation included; no code snippets or media provided.

Summarized with AI on February 8. AI used: gpt-5.
1

Hi Team,

Need to know payment id field max-length, and specifications (any allowed special characters?)

Documentation only mentions it is a String:

| id required | Unique identifier for the payment attempt. Used as the idempotency key. It can be assumed that requests with a given ID are identical to any previously received requests with the same ID. This ID must be surfaced to the merchant so that they can correlate Shopify orders with payments managed by the Partner app. | String |> | - | - | - |

Thanks