Mass texting and bulk SMS broadcast software, personalized per contact at any scale.

What drives the number

What a mass text actually costs, and the two things that change it.

The price per message is what most people compare, but it is the smaller part of the cost. What changes a bulk SMS bill most is the number of segments and the size of the list, and only one of those is obvious.

A single SMS segment is 160 characters. If a message is one character longer, it splits into two segments billed separately, at 153 characters each, because the standard uses the difference to join the parts back together on the phone. So a 161-character message costs double a 160-character one. Anything that makes a message longer without your noticing can push it over, such as a long merge field, an emoji, or a link that was not shortened.

Emoji deserve a specific warning. A single emoji switches the whole message to a different character encoding, which cuts the limit per segment from 160 characters to 70. One smiling face can turn a one-segment message into three. This is why the composer shows the live segment count as you type.

• Write to 160 characters and check the counter before the message reaches the review screen.
• Shorten links, which also lets you count clicks.
• Budget by segment, not by message. A 40,000-contact send at two segments is an 80,000-message bill.
• Test on your own staff list first, where a mistake costs nothing.

The same list gets worse every month you do not send to it.

A texting list loses value over time, and faster than most owners expect. People change numbers, carriers reassign old numbers, and interest that was real at opt-in fades. None of that is visible from the list itself, which still shows the same count it showed a year ago.

In practice, a list you have not messaged in six months is worth less than its size suggests. Sending to it without warning leads to higher opt-out rates, more carrier filtering, and a significant share of messages reaching people who no longer recognize you. The first send after a long silence is the most expensive one you will make, in reputation as well as money.

Programs that last treat a regular sending schedule as maintenance, not pressure:

• Send regularly enough to stay recognized. Monthly is the minimum for most lists. Sending only quarterly is close to starting over each time.
• Sort your list into groups before sending more. A smaller group that wants the message does better than a larger one that only tolerates it, and it costs less to send.
• Watch the opt-out rate per send, not in total. A rising rate is the earliest reliable sign that your sending schedule or targeting has gone off course.
• Ask for permission again rather than assume. If a group has not heard from you for a long time, ask those contacts to confirm before you start sending again. A smaller confirmed list is worth more than a large outdated one, and it is the safer position.

This topic appears on a mass texting page rather than a compliance page because it is mainly about cost, not law. Texting people who no longer want to hear from you is the most expensive thing a bulk SMS program can do, long before anybody complains.

Sent is not the same as delivered

Why a message the platform accepted still might not arrive.

After a bulk send, the platform reports that the message went out. That report means the carrier accepted it, which is not the same as a phone displaying it. Carriers filter heavily and without notice, and they are not required to explain why. Understanding the few things that trigger filtering is worth more than any amount of rewording the message.

• Unregistered sending. This is the largest single factor. Application-to-person traffic (messages sent from a software platform) from an unregistered number is the first thing carrier filters slow down. Registration is covered separately on this site, and it is the change that improves delivery rates most.
• Public link shorteners. A shared link-shortening domain carries the reputation of everyone else who uses it, including spammers. A branded or dedicated short domain keeps your reputation separate from theirs.
• Content in the categories carriers watch most closely. Lending, cannabis, gambling and adult content face heavier scrutiny regardless of how legitimate the sender is. If you work in one of these areas, expect closer review and plan for it.
• Sudden volume from a new number. Going from nothing to forty thousand messages in an hour on a new number looks exactly like a spam campaign. Increase your volume gradually instead.
• High opt-out or complaint rates. Filters treat these as a sign of low quality. This is where an outdated list starts to reduce the number of messages delivered.

In practice, whether your messages reach people's phones depends mostly on what you do before the send, not on fixes afterward. Register the number, increase its volume gradually, keep the list current, and use a link domain you control. A program doing those four things rarely has a filtering problem worth investigating.

When delivery does drop, look at what changed rather than at the message. A new number, a new link shortener, a group of contacts that had not been messaged in a long time, or a first send after a long gap will explain most sudden drops. The wording is almost never the cause, which is why rewriting it almost never helps.

The four numbers worth reading after a send.

Most bulk SMS reports lead with the number of messages sent, which is the least useful figure. It measures how much you spent, not what happened. Four other numbers tell you whether the send worked.

• Delivery rate. This is the number delivered divided by the number sent. In a healthy program, it is high and stays high. A drop points to filtering or list quality and is the first thing to check, because the other numbers are measured against a smaller real audience than you think.
• Click rate on the link. This is the only direct measure of whether people responded to the offer. Measure it for each group rather than for the whole send, because one strong group can hide three weak ones.
• Opt-out rate for this send. Measure it for each send, not as a running total. A rising figure is the earliest reliable warning that your sending schedule or targeting has gone off course, and it changes before revenue does.
• Reply volume. Replies are easy to ignore on a broadcast, but they are often the most valuable result, because a reply comes from a person who wants something. A send that brings in replies nobody reads is wasted.

Read these numbers together. A high click rate with a poor delivery rate means a small audience is responding well. That is a different problem from a large audience ignoring you, and the two call for opposite responses.