Can customers update custom profile fields and photos without a portalSlug?

Yes. After sign-in, updateProfile() can change the customer's basic fields and customer-editable parameters. Pass custom values under profileParameters, keyed by a parameter's schema ID, system ID, name, or normalized name. The backend checks edit permissions and the parameter's configured type and options.

portalSlug is optional for these customer-editable parameters. When supplied, it selects an active portal and additionally restricts edits to parameters enabled in that portal. Staff-only parameters cannot be changed through a customer session.

Profile photos can be saved as a URL or uploaded from a browser File or Blob with updateProfile() or uploadProfilePhoto(). Supported image formats are JPEG, PNG, GIF, and WebP, up to 5 MB. Hosted profile forms support photo upload controls and data-tiquo-profile-parameter fields.

Address lists and the built-in Tax ID field have additional requirements: supply a portalSlug whose portal enables the relevant profile fields. If Town/City or Postcode is a custom parameter, it follows parameter rules; a structured address follows address-editing rules. displayName, createdAt, and firstActiveAt are read-only.

See DOM customer data, Hosted profile forms, and Update Profile.