SleekFlow charges for SMS and MMS based on message type, delivery status, and carrier fees. This article explains how units are calculated (segments vs. messages) and how costs differ between inbound, outbound, delivered, and failed messages.

Billing units

SMS and MMS are billed differently. SMS is measured in segments, while MMS is measured as full messages.

• SMS (per segment):
  • SMS is broken into segments depending on length:
    • 1 segment = up to 160 characters (GSM standard)
    • or up to 70 characters if emojis or non-Latin text are used
    • Longer messages are split into multiple segments, and each segment is billed separately

• MMS (per message):
  • MMS is billed as one unit per message, regardless of text length or media included. Unlike SMS, MMS is not split into segments.

Factors that affect pricing

The cost of a message is also influenced by its direction and whether it is delivered successfully.

• Message direction:
  • Outbound messages: You pay for every message you send (SMS segments or MMS messages).
  • Inbound messages: Messages received from customers are also billed. Inbound rates are usually lower but apply to both SMS and MMS.
• Delivery status:
  • Delivered messages: Charged normally once handed off to the carrier.
  • Failed messages: If a message fails to deliver (e.g. invalid number, unreachable device), a failed message processing fee may apply. This fee is typically lower than the standard message rate and depends on the carrier.
    • ℹ️ Processing fees only apply when the carrier has already attempted delivery and returned an error status.

Carrier fees

In addition to SleekFlow’s standard SMS and MMS rates, some mobile carriers add their own surcharges. These are billed per message or per segment, depending on whether the message is SMS or MMS.

• When they apply: Carrier fees can be charged on both outbound and inbound messages.
• Why they vary: The fee depends on the destination country, the recipient’s mobile carrier, and their policies.
• How they appear: Carrier fees are listed separately from SleekFlow’s message costs in your invoice.
• Calculation basis: The fee is determined by the recipient’s carrier, not the sender.

Pricing

The following tables show SleekFlow’s US base messaging rates and carrier-specific fees.

United States - Messaging cost (in USD)

United States - Carrier fee (in USD)

In addition to SleekFlow’s base rates, US carriers charge an extra per message/segment fee. This applies to both SMS and MMS.

• Fees are charged per unit (per SMS segment or per MMS message).
• The amount depends on the recipient’s mobile carrier.

Phone number fee

To use SMS, you need to keep an active phone number connected to SleekFlow. This number has a monthly fee in addition to message costs.

• The fee is charged per phone number you keep active.
• It appears as a recurring charge on your invoice.
• Message costs and carrier fees are billed separately.