How to Collect Phone Numbers for SMS Marketing on Shopify

Updated Nov 9, 2026 4 min read

TL;DR

Asking for a phone number costs fewer signups than most merchants expect. Here is how to add a phone field to your Shopify popup, get proper consent and send those numbers to your SMS tool.

How to Collect Phone Numbers for SMS Marketing on Shopify

SMS has a reputation as the channel that gets read. The problem is getting the number in the first place, because many merchants assume shoppers guard their phone numbers much more closely than their email.

Our data says the cost is real but smaller than you think.

Data note: Figures come from aggregated, anonymous PopupBoost data, February to November 2026.

How many shoppers share a phone number today

Across all PopupBoost subscribers, 8.0% left a phone number. That is 34,976 phone numbers collected by 63 stores.

The share is low mostly because few stores ask. Most campaigns collect only email. Among the stores that do ask, phone collection is a steady side channel next to email.

What a phone field costs you

We compared the median engagement rate of campaigns with and without a phone field:

With a phone field: 7.4%
Without a phone field: 8.1%

Now compare that with a name field:

With a name field: 5.2%
Without a name field: 8.3%

So a phone field is a small cost and a name field is a large one. If you want to collect more data, a phone number is the better thing to ask for.

Optional or required?

There are three common setups:

Email required, phone optional. The safest option. People who do not want texts can still join.
Phone required, email optional. For stores where SMS is the main channel.
Phone only. The simplest form for a pure SMS list, with the clearest consent message.

Start with the first. After two weeks, check how many signups include a phone. If you want more, test a stronger prize for shoppers who add their number.

Write a clear consent line

Consent rules for marketing texts are strict in many places. In the US, marketing texts generally need clear prior consent. The EU and UK also require consent for electronic marketing.

A good consent line is short and specific:

"By entering your number, you agree to receive marketing texts from [Store]. Message frequency varies. Reply STOP to unsubscribe."

Put it right next to the phone field, not hidden below the button. If you are unsure about the rules in your markets, ask a lawyer. This post is not legal advice.

Use the right game for the ask

When you ask for more, give more back. A game makes the trade feel fair because the shopper is playing for a reward.

Scratch cards and slot machines had the highest median engagement rates in our data (17.9% and 15.9%). If you are adding a phone field, pairing it with one of these formats helps offset the small drop. Read scratch card vs spin wheel to choose.

Get the numbers into your SMS tool

A phone number in a spreadsheet does nothing. Connect your popup to your SMS platform so new subscribers get a welcome text within minutes.

PopupBoost sends subscribers to Klaviyo, Omnisend, Mailchimp and Shopify customers. After you connect, send a test signup with a phone number and check that your SMS tool receives it. Our guide to syncing popup signups with Klaviyo and Shopify Email covers the setup.

Format numbers correctly

Phone numbers often fail to sync because of formatting. Three tips:

Use a phone field with a country code picker, so numbers are stored in international format.
Show a clear error when the number is too short or has letters.
Pre-select the country your store sells to most.

Send a welcome text that earns the next one

Your first text sets the tone. Keep it short, deliver what you promised and make opting out easy:

"Welcome to [Store]! Here is your 10% code: HELLO10. Valid for 7 days. Reply STOP to opt out."

Then hold back. SMS works because it feels personal. Too many texts in the first week will push people to unsubscribe.

Your next step

Add an optional phone field to your current popup, write a clear consent line and connect it to your SMS tool. Leave everything else the same for two weeks and compare engagement with your previous numbers.

If engagement drops less than one point, you have a second channel almost for free. For the bigger picture of list building, read how to build an email list on Shopify from zero.

Frequently asked questions

Does asking for a phone number reduce popup signups?

A little. In PopupBoost data, campaigns that collected phone numbers had a median engagement rate of 7.4%, compared with 8.1% for campaigns that did not. That is a much smaller drop than asking for a name, which lowered the median from 8.3% to 5.2%.

Should the phone field be required or optional?

Optional is the safer start. Shoppers who do not want texts can still join by email, and you collect phones from the people who are happy to give them. Make it required only if SMS is your main channel and you have tested the impact.

Do I need consent to send marketing texts?

Yes, in most countries. In the US, marketing texts generally require clear prior consent, and the EU and UK also require consent for electronic marketing. Use a clear consent line next to the phone field and check the rules for the countries you sell to. This is not legal advice.

Article by

PopupBoost Team

We build PopupBoost, the gamified popup app for Shopify. Our posts use anonymized data from the campaigns running on PopupBoost stores, so the advice comes from real results, not guesses.