# How numbers are assigned

> Every lead gets one permanent number while your pool rotates behind the scenes, so volume spreads without a lead ever seeing two numbers.

One lead, one number. Your pool does the rest.

## The problem this solves

If every lead texts the same number, that number absorbs all the volume and its reputation collapses. But if a lead texts one number and gets a reply from a different one, they see two strangers in their Messages app and stop trusting you.
So the rule is simple: each lead is assigned exactly one number, permanently. The rotation happens across leads, never inside a conversation.

## How it runs

  The lead taps your buttonBefore their Messages app opens, your page asks Beam which number to use. Beam picks the line carrying the fewest conversations, records the pairing, and returns a ready-made link with the first message already written.
  They send the first textBecause they opened the conversation, there is no warm-up ceiling on your reply, and the thread cannot be reported the way a cold message can.
  Every reply uses that same numberFollow-ups, the assistant, a rep in the inbox, a reminder weeks later: all of it leaves from the number they already know.

## What each side sees

  
|  | The lead | You | 
  
| Numbers | Exactly one, forever | Your whole pool | 
  
| Threads | One conversation | Every conversation in one inbox | 
  
| When you add a line | Nothing changes | New leads start using it | 

## Sizing the pool

A number is not a bucket you can fill. Each line safely opens a limited number of new conversations per day.

  
| Lines | New cold conversations per day | 
  
| 1 | 50 to 100 | 
  
| 3 | 150 to 300 | 
  
| 5 | 250 to 500 | 
  
| 10 or more | 500 to 1,000 | 

The exception worth building aroundThose limits apply when you message first. When the lead texts you first, the ceiling does not apply at all. That is the difference between needing a hundred numbers and needing three. See The text-us-first funnel.
Sizing rule: take the number of new cold conversations you need to start per day, divide by 50, and that is your minimum line count. Leads who come to you barely count against it.

## The rules underneath

  - Sticky by contact. A phone number is paired to a line the first time we see it, and the pairing is never reshuffled.
  - Least busy wins. New leads go to the line carrying the fewest conversations, so a burst spreads instead of piling up.
  - Blue preferred. If the lead can receive blue-bubble messages they get a blue line, otherwise the text line.
  - Inbound re-pins. If someone texts a different line of yours, that thread moves to the line they actually used. Nobody is answered from a number they did not write to.
  - A shared reserve, not spares. Keep a small pool in reserve rather than a dedicated backup per client. When a line degrades, a thread moves and the conversation continues.