Problem with custom fields

Regular Participant

Problem with custom fields

I am sending JSON requests to the API formatted as follows. It all works except for the custom field, "Username." That's set up as a custom field in our account, but when I try to refer to it in my code as "Username," it generates an error. I've tried using "Custom Field 1" which just creates a "custom_field_1" field in my account.


Surely there's a way to put data into the existing "Username" field, right?


Here's how the request looks:


{"import_data": [
		"first_name": "Joe",
		"addresses": [{
		"address_type": "PERSONAL",
		"state_code": "GA"
	"email_addresses": [
	"custom_fields": [{
		"name": "Username",
		"value": "JoeUser"

"lists": [
	"column_names": [



Thank you for reaching out to Constant Contact API Support.


The cause of this is that the API is currently only able to interact with custom fields that follow a very specific naming convention, which is covered here:


While it is possible to create custom fields with other naming formats using our website, the API cannot use custom fields that do not use the format described at the above link. This is because our API still has limits from our older Contact Management platform. While I can't provide a timeframe for when we will have updated functionality, limits, and features, I can say we are working to get them out as quickly as we can.


Let me know if you have any other questions and I'll be happy to help in any way I can!


David B.
API Support Specialist

Is there any updated information on this particular issue?



While I can't guarantee this timeframe, I can tell you that we are working on our V3 version of our API which should have these features, and we hope to have general availability for contacts calls by the end of June.


Please let me know if you have any other questions!



David B.

API Support Specialist

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