Why some text messages appear in two separate threads on the recipient's phone

If a customer reports that messages you sent from Roezan are showing up in two separate threads on their phone - one with a "+1" prefix and one without, this is a carrier-side limitation that affects some messages sent to Verizon Wireless (and potentially others).

It is not a bug in Roezan - this on the carrier side and affects only certain recipients.

This article explains what's happening and what you can do about it.

What it looks like

Your customer sees two separate conversation threads on their phone, both from your Roezan phone number:

• Thread A - sender shown as +1 (XXX) XXX-XXXX (with country code)

• Thread B - sender shown as (XXX) XXX-XXXX or XXX-XXX-XXXX (no country code)

Why this happens

The difference is between messages that are sent as MMS and SMS.

As a side note - Roezan auto-converts longer messages (anything 3+ segments) to MMS to save you money. It's more expensive to send a 3+ segment SMS than a MMS, and MMS gives you much more flexibility for the same or less cost.

Here's where the threading issue comes in:

1. Your sender number is handed off to the recipient's carrier in proper E.164 format (+1XXXXXXXXXX) for both SMS and MMS. For Roezan the handoff format is correct and identical for both.

2. Verizon's MMSC reformats the sender ID before delivering the MMS to the recipient's device. The country code (+1) is stripped or the number is re-presented in a different format. This is a carrier-side behavior outside of our control.

3. iPhone threads messages by the exact sender ID string. When the same number arrives formatted two different ways, iPhone treats them as two separate contacts and creates two separate threads.

So in short: your long messages go out as MMS, your short messages go out as SMS, Verizon formats the sender number differently on the two channels, and the recipient's iPhone splits them into two threads.

Workarounds

We haver reached out to the carrier requesting this to be updated, but in the meantime here are a few workarounds -

Option 1: Keep individual messages under ~300 characters to always send as SMS (simplest)

If you stay under the 3-segment threshold, every message goes out as SMS and there's no protocol mismatch for the recipient's carrier to handle. Threading will be consistent across all carriers.

Rough character limits for plain text:

• 1 segment: up to 160 characters

• 2 segments: up to 306 characters

As an alternative here, you could break a long message into two shorter messages

Instead of one 400-character message that auto-converts to MMS, split it into two 200-character messages. Both will go out as SMS and will thread together with the rest of your conversation.

Option 2: Always send as MMS

If you want all your messages to go as MMS (so they thread together with the long ones), you can attach an image to your shorter messages.

Any message with media attached is automatically sent as MMS, which forces all messages onto the same protocol path and produces consistent threading.

Frequently asked questions

Will my recipient still get both messages?
Yes. Both messages are delivered successfully to the recipient. They're just shown in two separate threads on the recipient's phone instead of one. The recipient sees and can reply to both - but the conversation is harder to follow.

Can Roezan fix this on our end?
This is a carrier-side behavior on their network and cannot be controlled from the sending side. We confirmed that the sender ID is delivered in proper E.164 format and that the reformatting happens after handoff to the carrier. The only reliable fix is to avoid mixing SMS and MMS in close succession to the same recipient (see options above).

Does this affect Android recipients?
Most Android messaging apps are more forgiving about sender ID formatting and will merge the two threads. The split is primarily an iPhone behavior.

Why does Roezan auto-convert long messages to MMS instead of sending them as multi-part SMS?
A 4 segment SMS gives you 612 characters and costs you 4 credits, whereas with MMS you get 1600 characters for only 3 credits. More bang for your buck. For accounts that send a lot of long messages, the savings add up significantly.