Update Participant

Change one person on a booking: their details, their sizes, or their answers to the questions the experience asks each person.

Endpoint

PATCH /v1/bookings/{id}/participants/{participantId}

Authentication

Requires an API key with the bookings:write scope.

Path Parameters

Parameter	Type	Description
id	integer	The booking ID
participantId	integer	The participant's id, from the booking's participants array

Request Body

All fields are optional. Only the fields you send change.

Field	Type	Description
first_name	string	First name
last_name	string	Last name
email	string|null	Email address
phone	string|null	Phone number
phone_country_code	string|null	Dialing code, for example +1
dob	string|null	Date of birth, YYYY-MM-DD
notes	string|null	A note about this person on this booking (max 2000 characters)
custom_field_values	object	Answers to the shop's own questions, keyed by field_id: {"88": "yes"}. An ID that is not one of your per-person questions is skipped
gear_sizes	array	This person's sizes: [{ "product_id": 41, "size": "M" }]. See Sizes

A name, email or date of birth belongs to the person, not the seat, so a change follows them to their other bookings. Changing the name to someone already on this booking returns duplicate_participant.

Sizes

Each gear_sizes row names an item the experience uses and the size this person needs.

• The size must be one the item has. It is matched without regard to case, so m saves as M.
• "size": null or "" clears the size.
• The item must ask each person their size on the experience (ask_size on its gear row, see Create Experience).
• Sizes are checked before anything else is saved, so a size the item does not have changes nothing.

A booking can be saved with a size still missing; staff fill it in later through this endpoint. Sizes alone can still be changed once people have checked in. Any other change is refused at that point.

{
  "gear_sizes": [
    { "product_id": 41, "size": "M" },
    { "product_id": 42, "size": null }
  ]
}

Response

Success (200 OK)

{
  "data": {
    "participant": {
      "id": 45,
      "customer_id": 310,
      "first_name": "Jane",
      "last_name": "Doe",
      "email": "jane.doe@example.com",
      "phone": null,
      "phone_country_code": null,
      "dob": null,
      "notes": null,
      "rate_category": { "id": 7, "label": "Adult" },
      "checked_in_at": null,
      "custom_fields": [
        { "field_id": 88, "label": "Can you swim 50m?", "field_type": "yes_no", "value": "yes", "formatted_value": "Yes" }
      ],
      "gear_sizes": [
        { "product_id": 41, "item": "Wetsuit", "size": "M" }
      ],
      "missing": ["Helmet size"]
    }
  },
  "meta": {
    "request_id": "req_abc123",
    "timestamp": "2026-10-06T09:00:00+00:00"
  }
}

gear_sizes and missing read the same as on Get Booking.

Errors

Status	Code	Description
401	authentication_required	No API key provided
401	invalid_api_key	Invalid API key
403	insufficient_scope	API key lacks bookings:write scope
403	forbidden	The booking belongs to another account
404	resource_not_found	The booking or participant does not exist
409	conflict	The booking is returned, completed or cancelled. Once people have checked in, only gear_sizes can change
422	validation_error	A field is wrong. A size problem is reported under gear_sizes, for example Wetsuit has no size "XXL". Its sizes are: S, M, L.
422	duplicate_participant	The new name belongs to someone already on this booking

Example Request

curl -X PATCH "https://app.equipdash.com/api/v1/bookings/123/participants/45" \
  -H "Authorization: Bearer eqd_live_abc123xyz789..." \
  -H "Content-Type: application/json" \
  -d '{"gear_sizes": [{"product_id": 41, "size": "M"}]}'