Pricing and limits

Pricing

Prices are set at runtime and can change without a release, so read them rather than hardcoding them. Each field's name gives its unit: the _cents fields are CAD cents, the _millicents fields (email and push) are CAD millicents, thousandths of a cent, and the auth_plans overage_tenth_cents_per_user is tenths of a cent. Sending is billed per segment: message_cost_cents × the segments the carrier splits the body into. Segments are counted the way the carrier counts them: typographic quotes, dashes and ellipses are smart-encoded to GSM-7 (160 characters, then 153 per segment), while emoji and most accented letters force Unicode segments (70, then 67). The charge is settled to the carrier's segment count after the send. A message the carrier rejects outright costs nothing, and so does a send to a reserved exchange (555-XXXX and similar), which is refused here; a message the carrier accepts but cannot deliver keeps its charge. A body over 10 segments is refused with 422 MESSAGE_TOO_LONG before any charge. verification_cost_cents covers a typical one-segment OTP; a long or non-GSM app_name can add a segment. phone_number_activation_fee_cents is the one-time fee on a local number, charged together with the first month and not refunded on release. For a toll-free number, phone_number_tollfree_monthly_cost_cents is the monthly rent and phone_number_tollfree_activation_fee_cents the one-time activation fee, 0 when there is none (its search result shows the same as activation_fee_cents); tollfree_verification_fee_cents is the one-time fee per toll-free verification application, paid by card when it is first submitted. inbound_message_cost_cents is charged per segment of every SMS received on a provisioned number, sender and carrier included, except STOP, START and HELP keywords; a received message is debited even if it takes the balance below zero, which pauses sending until the next top-up.

# Current prices. Public: no API key needed.
# SMS, verification and number prices are CAD cents; email and push
# prices are CAD millicents (thousandths of a cent: 250 is $0.0025, or
# $2.50 per 1,000); an auth plan's overage is tenths of a cent per user
# (25 is $0.025).
# The email_* fields appear while email is available, push_* while push is.
curl https://api.honkio.ca/v1/pricing

# Response 200:
# {
#   "message_cost_cents": 3,
#   "verification_upcharge_cents": 25,
#   "verification_cost_cents": 28,
#   "phone_number_upfront_cost_cents": 250,
#   "phone_number_monthly_cost_cents": 250,
#   "phone_number_activation_fee_cents": 100,
#   "phone_number_tollfree_monthly_cost_cents": 9900,
#   "phone_number_tollfree_activation_fee_cents": 0,
#   "tollfree_verification_fee_cents": 49900,
#   "inbound_message_cost_cents": 3,
#   "email_price_millicents": 250,
#   "email_attachment_included_bytes": 2097152,
#   "email_attachment_price_millicents_per_mb": 200,
#   "email_attachment_max_bytes": 26214400,
#   "email_inbound_price_millicents": 250,
#   "email_inbound_included_bytes": 1048576,
#   "email_inbound_price_millicents_per_mb": 200,
#   "push_price_millicents": 50,
#   "push_free_monthly": 0,
#   "auth_plans": {
#     "free": { "fee_cents": 0, "included_users": 250, "overage_tenth_cents_per_user": null },
#     "pro": { "fee_cents": 4900, "included_users": 2500, "overage_tenth_cents_per_user": 25 },
#     "business": { "fee_cents": 24900, "included_users": 10000, "overage_tenth_cents_per_user": 20 }
#   }
# }

Test-mode requests are priced identically in the response but never charged, so you can see what an integration would cost before spending anything.

Toll-free numbers send and receive at the same price per segment as local ones. Before one can send SMS, it needs a one-time verification: $499.00 per application, paid by card rather than from your balance. See Toll-free numbers.

Sending limits

HonkIO is built for transactional and relationship messaging, not campaigns, and every customer’s deliverability rides on a shared carrier profile. These limits keep bulk marketing off the platform; a clinic, a contractor or a SaaS sending codes will not notice them. The sending limits apply to live mode only; the link-shortener rule, the reserved and undeliverable destination checks, and the broadcast group-size cap run in both modes.

• Daily cap: new accounts can send 250 live messages per rolling 24 hours. It does not lift on its own. 30 days after your first live message you can request a higher volume from the dashboard; approval sets 1,000 a day or the figure you asked for. Refused sends return 429 DAILY_LIMIT_REACHED with your limit and count. The request needs a verified business (see Business verification below).
• Identical messages: the same body may reach at most 250 distinct recipients per 24 hours (429 FANOUT_LIMIT_REACHED). Personalized messages are unaffected.
• Per-number rate: a 10-digit number sends 10 segments a minute, the pace the carrier sends them at, so a 3-segment message takes three of them. A send is refused while a full minute’s worth of segments or more is already waiting (429 NUMBER_RATE_LIMITED with Retry-After). A verified toll-free number sends up to 1,200 segments a minute. A contact-group broadcast skips this rate, but may not put more than 1,200 segments in a 10-digit number’s queue (429 NUMBER_QUEUE_FULL); toll-free numbers have no such cap.
• Broadcasts: up to 250 recipients per contact-group broadcast and 3 broadcasts per 24 hours (422 BROADCAST_TOO_LARGE, 429 BROADCAST_LIMIT_REACHED).
• Toll-free numbers: sends from a verified toll-free number have their own limits, counted apart from sends from your local numbers, so neither uses up the other. There is no probation: 10,000 live messages per rolling 24 hours (less if HonkIO has held your account below its approved daily limit), the same body to up to 2,500 distinct recipients, and contact-group broadcasts of up to 2,500 recipients, 30 per 24 hours. A refusal says which limit was hit (details.tier is toll_free or local). The per-recipient cap, the automatic pause, the link-shortener rule and the top-up caps are the same for both.
• Link shorteners (bit.ly, tinyurl and similar) are refused in both modes because carriers filter them (422 LINK_SHORTENER_BLOCKED). Use the full URL.
• Delivery warning, then automatic pause: if more than 10% of your last 50 live messages fail at the carrier, you are emailed (and account.delivery_warning fires) without any pause. If, over your recent sends, more than 1% of recipients opt out (at least five people; a STOP reply and an opt-out you record yourself both count) or more than 5% of messages are rejected by carriers, live sending pauses for 24 hours and you are emailed (403 SENDING_PAUSED with the resume time; account.sending_paused fires).
• Top-ups: the balance cannot exceed $500 and top-ups are limited to $1,000 per 30 days. A verified business can request higher limits.
• Per-recipient cap: 30 messages to one recipient per hour and 100 per 24 hours (429 RECIPIENT_RATE_LIMITED with Retry-After). A two-way conversation never gets near it; a script retrying one number does.
• Undelivered messages are billed: a message the carrier accepts but cannot deliver keeps its charge. A reserved exchange (555-XXXX, N11 exchanges such as 411 or 911, carrier test codes, exchanges starting with 0 or 1) is refused for free with 422 RESERVED_DESTINATION, in test mode too, and a reserved area code (555, 911 and the like) as non-Canadian. Anything that retries should send an Idempotency-Key header so a retry can never become a second charge. An hour of unusual spend triggers an email and account.spend_warning.
• Undeliverable numbers: after 3 consecutive carrier failures to one number within 30 days, from any HonkIO customer, sends to it are refused without charge (422 UNDELIVERABLE_NUMBER with the failure count, when it was listed and when it expires) for 90 days, then retried in case the number was reassigned.
• Inbound cap: each account can receive at most 1,000 segments per rolling 24 hours by default, a long text counting as several (support can raise it). Texts past the cap are recorded without their content, not charged, and fire no message.received; the first one in a window sends account.inbound_sms_capped. STOP, START and HELP are always processed.

Sending to a list works through the per-number pace with an example and shows how to handle 429 refusals and retries.

curl https://api.honkio.ca/v1/send-limit \
  -H "Authorization: Bearer mk_live_YOUR_KEY"

# → { "daily_limit": 250, "sent_last_24h": 12, "remaining": 238,
#     "recipient_rate_per_hour": 30, "recipient_rate_per_day": 100,
#     "probation": { "ends_at": "2026-09-26T14:02:11.000Z", "eligible_to_request": false },
#     "paused_until": null, "requests": [] }

Read your current limits and usage with GET /v1/send-limit, and file a request with POST /v1/send-limit/requests. Every figure above is a platform default that can be raised per account.

Auto top-up

Auto top-up charges your saved card and credits your balance without a manual top-up. Turn it on from the billing page in the dashboard: you choose a low-balance threshold and an amount, and the first top-up saves the card for later charges.

• It triggers when your balance falls below your threshold, and in the 24 hours before monthly number rent is due if your balance would not cover it. The smallest threshold is $5.00 and the smallest amount is $10.00. The amount must be at least as much as the threshold, so one top-up brings your balance back above it.
• Your balance is checked about once a minute, so a burst of sending can still reach $0 between checks. Pick a threshold that leaves room for your peak sending.
• Each charge counts toward your top-up limits (maximum balance and 30-day total). A charge that would exceed them is skipped, and the dashboard says so.
• If we can’t charge your card, auto top-up pauses and we email you. It also pauses when one of your payments is refunded, and after 3 charges in 24 hours. A manual top-up does not turn it back on. To resume, use Top up to resume in the Auto top-up section of the Billing page, which is a new top-up that saves your card again. If your account is under review, auto top-up stays paused until HonkIO support lifts it, and a top-up does not resume it. GET /v1/auto-topup returns your settings and recent attempts, and the account.auto_topup_succeeded and account.auto_topup_paused webhook events report each result.

Business verification

Requests for more phone numbers, a higher sending volume, higher top-up limits and toll-free verification are open to verified businesses. Verification is free: fill in your business and a contact person under Settings, Business verification (or PUT /v1/business-verification, then POST /v1/business-verification/submit), and our team checks them against public registries and your website, usually within a few business days.

• Sole proprietors can verify without a CRA business number: give your legal name, the name you trade under, your address, a public link that shows your work and a sentence on what you do. Every other kind of organization needs its business number, and toll-free verification always does.
• Until then, the request routes answer 403 BUSINESS_VERIFICATION_REQUIRED; a toll-free submission from a verified profile with no business number answers 403 BUSINESS_NUMBER_REQUIRED.
• Request higher top-up limits with POST /v1/account/topup-cap-requests or from Billing. Limits already granted stay if a verification is later revoked. A verified business can change its details at any time: the changes go back to HonkIO for review, and the business stays verified, as HonkIO verified it, until the review ends (verified stays true on GET /v1/business-verification, and verified_details keeps the details HonkIO verified, which toll-free verification uses).