Missing customer id from order response.

[Faaque]

Hello Team,

I’m using the Order API to retrieve order details, and I’ve noticed that the Customer ID field is not consistently populated across all orders.

As a reference, here's an example of an order where the customer ID is returned correctly:

However, for many other orders, the Customer ID is missing in the API response. Could you please look into this inconsistency?

 
Order ID: 30vqVahlPZuluSidnCKKz3meV
Customer ID: J83AGHGF6YJVNYDW3YFB7TRJR4

The following orders do not include a customer ID in the response

1VjpNuEjoWn0hJmNlTTi7tRqivYZY
3ijiBfeVhpEDPNV2z1Ue92lepuWZY
F5l7Zi71BGww5iuOUIwhJoWqZgZZY

[Summer2024 · Accepted solution]

Hi, @Faaque ! Welcome the Square Community! 

Order ID is optional and is only populated when a customer profile was explicitly linked to the order at creation or via an update. Common cases where it’s not set:

• Guest/anonymous checkout (no profile selected or created).
• POS orders where the team didn’t attach a customer at checkout.
• Online orders where the buyer didn’t sign in and no post-purchase linking occurred.
• 3P/legacy flows (e.g., older integrations, terminals) that don’t send customer_id with the order.
• Merged/deleted customer profiles—the order remains, but its customer_id link can be lost.

Square may still know who paid (on the Payment), but the Order object itself won’t show customer_id unless it was linked.

How to recover the customer for “missing” orders

You can usually backfill from Payments or fulfillment data:Look up the Payment(s) for the order
Use Payments API to find the payment tied to the order; payments often have customer_id even when the order doesn’t.POST /v2/payments/search
{
"query": { "filter": { "order_filter": { "order_ids": ["<ORDER_ID>"] } } }
}

If payments[i].customer_id is present, that’s your customer.If there’s no customer_id on the payment, try:

• buyer_email_address on the Order
• fulfillments[].shipment_details.recipient.* (name, email, phone)
• Any invoice/checkout link metadata you passed

I hope this helps.