API reference / Track results

Outcomes and what to do

Every send ends with a status of success or failure, a numeric reason_code and a text reason. They arrive on the status webhooks and on callback_url. See Results of your sends.

Branch on reason_code, not on reason. The text can be reworded; the number can't.

Retry? means:

Yes: resend now.
Later: resend after some time passes.
After fixing: change something first. Resending unchanged fails the same way.
No: don't resend to this contact on this channel.

Delivered

The send went out. Nothing to do.

Code	Reason	Retry?	What to do
0	Success	n/a	The voicemail was left, the call was answered, or the text or email was sent.

Mailbox reached but couldn't take a message

The call reached the contact's carrier, but the mailbox couldn't record a voicemail. Retrying won't help until the contact fixes their mailbox. Check what the contact agreed to on Consent, then reach them on another channel they agreed to, such as a text. The proof of delivery recording plays what the mailbox said.

Code	Reason	Retry?	What to do
4001	VoiceMail Not Setup	No	The contact never set up their mailbox.
4002	VoiceMail Full	No	The contact's mailbox is full.

Didn't reach the contact

This attempt didn't reach the contact. Unless the row says otherwise, retry later, inside the contact's calling hours and within your contact frequency limit. See Delivery rules.

Code	Reason	Retry?	What to do
4000	VoiceMail Not Detected	Later	The line answered, but no voicemail greeting was detected. Try another time of day.
4003	Temporarily unreachable	Later	The contact's number was temporarily unreachable, often because their phone carrier is having network problems. Try again later. If many sends fail this way at once, contact support with a `drop_id`.
4004	Number not reachable	Later	The call couldn't connect. If it repeats, check the number with the contact.
4005	No Answer	Later	Nobody answered.
4006	User Busy	Later	The line was busy.
4008	Spam detected	Later	The carrier rejected the call as unwanted, or no audio was detected on the line. Check your caller ID's reputation, or send from another phone line.
4011	TCPA Hours	Later	A text outside the contact's allowed hours (federal and state-specific calling hours in their time zone). Resend inside the window. Voice sends wait for the window instead.
4012	Timeout	Later	The call or AI conversation didn't finish in time.
4013	Too Many Attempts	Later	The number reached your contact frequency limit (default 3 attempts in 3 days), counted across your account. Resend after the window, or change the limit. The webhook's `frequency_limit` object shows the limit and the count. Test numbers are exempt.
4023	Network Blocked	Later	The carrier's network blocked the call as unwanted. Check your caller ID's reputation and registration before resending.
4024	Carrier Intercept	No	The carrier played an intercept message, usually for a disconnected or changed number. Check the number with the contact.
4025	Reached Automated Menu	No	The call reached an automated menu, not a person or a mailbox.
4026	Call Screening Detected	No	The call reached a call-screening service.

Number can't be used

The number itself can't take this send. Fix or replace it on the contact; resending to the same number fails the same way.

Code	Reason	Retry?	What to do
3011	Must be E.164 format	After fixing	A number isn't in E.164 format (`+`, country code, number). Applies to the recipient and to number fields such as `caller_id` and `transfer_to`.
3012	Phone number not valid	After fixing	The number is too short to be valid, or the contact has no number in the `phone_selector` slot you named.
4007	Not Mobile	No	The number isn't a mobile, and `mobile_only` is on for the send, the campaign or the account. Use a channel that reaches landlines, or turn `mobile_only` off.
4009	Public Safety Number	No	The number is an emergency or public-safety number. Remove it from your list.
4019	RND Reassigned	No	The Reassigned Numbers Database says the number changed hands after the contact's consent. Remove it and ask the contact for their current number. We check the database only when you add your own RND credentials; register with the RND directly to qualify for its safe harbor.
4021	RND Error	Later	The reassigned-number check, run with your RND credentials, failed for this number. Check the credentials, then retry later; if it repeats, contact support with the `drop_id`.

Not allowed: stop

You may not contact this person this way. Don't resend and don't work around the block.

Code	Reason	Retry?	What to do
4015	Geographic Region Blocked	No	The destination country is sanctioned or turned off on your account, or the caller ID or your account location isn't allowed to reach it. If you should be able to reach that country, contact support.
4016	Internal DNC	No	The number is on your do-not-contact list. Remove it only if the contact asked to hear from you again.
4017	Known Litigator	No	The number is on a known TCPA litigator list. We check with your own Blacklist Alliance or WebRecon key when you add one on the Integrations page, and with ours otherwise.
6004	Opt-in Flagged	No	The contact's opt-in was flagged as spam. Don't send until you have a new, documented opt-in.
6005	Opt-in Revoked	No	The contact revoked consent, for example by replying STOP. Only a new, documented opt-in allows sending again.
6006	Opt-in Pending	Later	The contact was asked to confirm their opt-in and hasn't confirmed. Resend once they do.
6011	Opt-in Missing	After fixing	Your account requires consent, and none is on file for this channel. Record the contact's opt-in, then resend. See Consent.

Your account or setup

Something about your account, your registration or the request has to change first. Nothing is wrong with the contact. Fix the cause, then resend with a new Idempotency-Key.

Code	Reason	Retry?	What to do
3000	No Funds	After fixing	Your balance is empty. Add funds or turn on auto-recharge, then resend.
3001	Audio file not valid	After fixing	The audio isn't usable: `media_id` isn't on your account, or `audio_url` couldn't be downloaded or isn't MP3 or WAV. Upload it with the Media API and send `media_id`.
3002	No Voice	After fixing	`voice_id` isn't valid, text-to-speech has no `voice_id`, or an AI call has bad `voice_ids` or `voice_rotation`.
3003	Campaign Deleted	No	The campaign was deleted while sending. Create it again if you still want to send.
3004	Not Included in Plan	After fixing	Your plan doesn't include this product. Change your plan, or use a channel it includes.
3007	Not authorized	After fixing	The key, secret or token was wrong, expired or missing the scope. Reported on `callback_url` only. See Authentication.
3008	No api container	After fixing	Your account's API setup is incomplete. Contact support with the `log_id` from the `callback_url` body.
3009	Too many phone numbers	After fixing	More than 100 phone numbers in one request. Split it.
3010	Nothing to do	After fixing	`phone_numbers` was empty.
3013	Invalid IVR or Route	After fixing	A phone line id isn't valid or isn't yours, or `inbound_routing` isn't `forward` or `byoc`. Use an id from `GET /phone/public/lines`.
3014	Not allowed audio_url	After fixing	Your account only allows approved audio, so `audio_url` is refused. Send a `media_id`, or `tts_body` with `voice_id`.
3015	No TTS	After fixing	`voice_id` was sent without `tts_body`.
3016	BYOC not enabled	After fixing	The send has a `byoc` object, but bring-your-own-carrier isn't on for your account. Remove it, or ask support.
3017	Invalid STI	After fixing	`byoc.sti_orig_id` isn't a valid UUID.
3018	Invalid Attestation	After fixing	`byoc.sti_attestation` isn't `A`, `B` or `C`.
3019	Invalid Callback	After fixing	`callback_url` isn't a valid URL. Pass a public http(s) URL, or leave it out.
3020	Missing Parameters	After fixing	A required field is missing or invalid: a text with no body, `template_id` or media; a `contact_id` that isn't yours; a bad `phone_selector` or digit; or a transfer key without `transfer_to`.
3021	TTS too long	After fixing	`tts_body` is over 1,200 characters, counted after merge fields are filled in. Shorten it.
3022	Not Allowed in Trial	After fixing	Trial accounts can only send to numbers verified on the account. Send to one, or choose a plan.
3023	US Identity Verification Required	After fixing	Sending to US numbers needs identity verification on your account. Complete it in the dashboard.
3024	Conversational Number Not Allowed	After fixing	The line is a conversational number, which only replies in the inbox. Send bulk texts from a line on a registered texting campaign.
3025	Daily Texting Limit Reached	Later	Your registered texting campaign reached the daily limit the carriers allow it. Resend after midnight Pacific time. Campaign texts don't get this code: the campaign holds the rest of its contacts and resumes at 9 a.m. Pacific the next day.
3027	Idempotency Key Conflict	After fixing	The `Idempotency-Key` was used in the last 24 hours with a different body or route. Use a new key for each new request.
3028	Invalid Idempotency Key	After fixing	`Idempotency-Key` isn't 1 to 255 printable ASCII characters. A random UUID works.
3029	Phone Line Has No SMS Campaign	After fixing	The `phone_line_id` has no registered texting campaign. Attach the line to an approved campaign, or use another line.
3030	Invalid Transfer IVR	After fixing	`transfer_ivr_id` isn't valid. Use a phone line id from `GET /phone/public/lines`.
3031	Transfer Destination Missing	After fixing	A transfer key was set with nowhere to transfer to. Add `transfer_ivr_id` or `transfer_to`.
3032	Invalid Media	After fixing	Bad `media_urls` or `media_ids`, more than 10 files, media with `template_id`, or media on a voice route.
3033	Media Not Found	After fixing	A `media_id` isn't on your account, was deleted, or has no uploaded file.
3034	Media Fetch Failed	Later	A media URL didn't answer `200` in time, or redirected. Host it at a public https URL.
3035	Media Too Large	After fixing	A file is over 1 MiB, or the files total over 5 MiB.
3036	Unsupported Media Type	After fixing	A file isn't JPEG, PNG, GIF, WAV or MP3, judged by its bytes.
3037	Media Blocked by Malware Scan	No	The malware scan flagged a file. Don't resend it.
3038	Media Scan Pending	Later	The malware scan didn't finish in time. A retry reuses the finished scan.
3039	Media Scan Failed	Later	The malware scan failed. The file may be fine; retry.
3999	Other	After fixing	`reason` names the cause, for example `No Agent`, `Agent Is Draft`, `Agent Not Active`, `No Template` or `Identity Not Verified`. Fix it and resend. If `reason` doesn't say what to change, contact support with the `drop_id`.
4010	No Caller ID	After fixing	No phone line to call from. The send named no `phone_line_id` and your account has no default phone line. Pass `phone_line_id`, or set a default line. Bring-your-own-carrier accounts can pass `caller_id` instead.
5000	Account Inactive	After fixing	Your account is cancelled, frozen or paused, which stops every channel. Contact support to restore access.
5001	Payment Required	After fixing	A subscription payment failed and the grace period passed, which stops every channel. Update your card, then resend.
5002	Trial Expired	After fixing	The trial period ended with no paid plan, which stops every channel. Choose a plan, then resend.
6000	Carrier Denied Use Case	After fixing	The carriers rejected your texting campaign's use case. Change the registration.
6001	Carrier Suspension	After fixing	The carriers suspended your texting campaign. Contact support before sending more.
6002	Pool Suspended	After fixing	Your number pool is suspended. Contact support.
6003	Pool Not Ready	Later	Your number pool is still waiting for carrier approval, or wasn't found. Resend once it's approved.
6007	Must Use Number Pool	After fixing	This send must go out from your number pool. For a `byoc` send, add `caller_id` or `pool_id`.
6008	Must Use Compliant Number Pool	After fixing	Your number pool has no opt-in confirmation message. Contact support to switch to a number pool that has one.
6009	Unregistered Brand	After fixing	Your account requires a registered brand, and the send had no valid `brand_id`. Pass one from `GET /automation/public/brands`, or register a brand.

Email-specific

These codes apply to email only. See Email.

Code	Reason	Retry?	What to do
5003	Not Entitled	After fixing	Your plan doesn't include email.
5005	Missing From Address	After fixing	No from address. Pass `mailbox_id` or `from`.
5006	Invalid From Address Format	After fixing	The from address isn't a valid email address.
5007	Sending Domain Not Found	After fixing	The from domain isn't one of your sending domains. Add and verify it.
5008	From Domain Mismatch	After fixing	The from address isn't on the sending domain.
5009	Domain Not Owned By Team	After fixing	The sending domain belongs to another account.
5010	Sending Domain Not Provisioned	After fixing	The sending domain's DNS records aren't verified. Finish the DNS setup.
5011	Sending Domain Not Verified With Provider	After fixing	The email provider hasn't verified the sending domain. Finish verifying it.
5012	Trial Daily Send Limit Exceeded	Later	The trial daily email limit is reached. Wait a day, or choose a plan.
5013	Daily Send Limit Exceeded	Later	Your daily email limit is reached. Wait a day, or ask support to raise it.
5014	Recipient On Do-Not-Contact List	No	The address is on your do-not-contact list.
5015	Recipient Opted Out Of Email	No	The contact opted out of email.
5016	Contact Not Found	After fixing	Your account requires email consent, and `contact_id` doesn't match a contact. Fix `contact_id`.
5017	No Email Consent On File	After fixing	Your account requires email consent, and the contact has none on file. Record it, then resend.
5019	Frequency Cap Exceeded (Bulk)	Later	The contact reached your bulk email frequency cap. Wait, or change the cap.
5020	Frequency Cap Exceeded (Transactional)	Later	The contact reached your transactional email frequency cap. Wait, or change the cap.
5030	Hard Bounce	No	The address bounced permanently and is now suppressed. Ask the contact for a new address.
5031	Soft Bounce	Later	The address bounced for a temporary reason.
5032	Spam Complaint	No	The recipient marked the email as spam and is now suppressed.

Temporary problem on our end

Something failed while handling the send. Retry. If the same code keeps coming back, contact support with the id named below.

Code	Reason	Retry?	What to do
3026	Daily Texting Limit Unavailable	Later	We couldn't check your texting campaign's daily limit, so the text wasn't sent. Retry.
5018	Consent Lookup Error	Yes	Email consent couldn't be checked. Retry; if it repeats, contact support with the `email_id`.
5021	Frequency Cap Lookup Error	Yes	The email frequency cap couldn't be checked. Retry; if it repeats, contact support with the `email_id`.
5022	Send Error	Yes	The email provider failed the send. Retry; if it repeats, contact support with the `email_id`.

Other codes

1000 (Pending) marks an attempt that isn't finished. Results never carry it.

Codes 3005, 3006, 4014, 4018, 4020, 4022, 4027, 5004 and 6010 are reserved and aren't returned.

While Drop Cowboy provides tools to support compliance efforts, customers remain solely responsible for obtaining proper consent, maintaining opt-out lists, and complying with all federal and state telemarketing regulations. Consult with your legal counsel to ensure your specific use case and consent mechanisms comply with applicable laws.