Collect phone numbers

What it solves & why businesses use it

SMS stands out when emails get ignored and ad costs keep climbing. While SMS is more expensive than email, it’s also far more likely to be read. That’s why it’s best for high-value segments where every message matters. It’s fast, direct, and ideal for urgent offers like 24-hour deals. Once you have a phone number, you can also reach users via WhatsApp or other messengers — cheaper than SMS, but just as immediate. The easiest way to collect customer phone numbers is by adding a widget to your website.

When & how to use it

Phone number collection works best when speed matters and for businesses in:

• Retail & e-commerce — for time-limited promotions, new products pre-orders or back-in-stock alerts.


• Local businesses & services — for appointment reminders, local updates, or exclusive offers.


• Events & entertainment — for reminders, last-minute changes, or early access perks.

You can collect phone numbers on their own — say, by offering a discount code via SMS — or together with an email. Use a single form with both fields, or go with a multi-step widget: email first, then phone number for a bigger reward. Trigger it when:

• A mobile visitor lands from a paid ad (capitalize on intent while it’s hot).


• A visitor browses high-intent pages (like product or pricing pages) for 20 seconds.


• A user starts exiting from the checkout or cart (offer to ‘text the deal’).

How it looks

Keep it sleek, simple, and mobile-friendly:

• Just one input field for the phone number.


• Strong headline with a clear benefit.


• One bold CTA button.


• Countdown timer for FOMO (optional).

Important: in many countries (including the US, UK, EU), you must include a Consent notice beneath the form, if collecting phone numbers for marketing. What to add:

• A short legal line explaining the user agrees to receive texts.


• Links to your Privacy Policy and Terms.


• If required by law (like the US TCPA), mention that ‘consent is not a condition of purchase’.

Place this notice right under the CTA button — always visible before submission. No hiding it in footnotes.

Pairs well with

Collection phone number widgets work even better when combined with other strategies. You can tie them to lead magnets by offering a discount or freebie delivered via SMS. They also complement email collection forms — giving users the option to choose how they want to stay in touch. Add a bit of fun with gamified widgets like Spin the wheel or Scratch card, where the prize is revealed only after entering a phone number.

How to set it up

Let’s build a collection phone number widget to help you connect with your audience more directly.

Step 1: Pick a template

No need to start from scratch — Claspo has over 1000 ready-made different templates. Just pick one that fits your goal and save time on design. A good widget should blend in with your site, so once you’ve picked your template, all that’s left is to change it.

Step 2: Customize it

Claspo’s editor makes it super easy to tailor everything — background, fonts, colors, and CTA buttons — to match your brand. You can also switch up the layout anytime. For example, if your template starts as a floating box, you can turn it into a pop-up or a content blocker in one click.

Our selected template comes with a fun background image, but you can easily swap it for your own (PNG, JPEG, WebP, or GIF) or choose one from Claspo’s built-in stock gallery.

To update the headline or body text, just double-click and type. Want to change the default country code? Click the phone number field, head to the General tab, and select your preferred default.

You can even restrict valid codes to collect only relevant numbers.

For the CTA button, you can change the design by selecting it and adjusting the settings on the right — from hover effect color and shadow to its shape and more.

Don’t forget to check the subscription status pages: Success, Existing, and Error. These are shown based on user actions. To edit them, scroll down or click their names in the bottom panel.

And last but not least — the Close button. Make sure it’s easy to spot without being intrusive. Click it to access styling options in the right-hand panel.

Step 3: Set display conditions

Give users a little breathing room before the widget shows up — 15 to 20 seconds is usually ideal. You can decide exactly when the widget appears using display triggers like:

• Time on page (default: 20 seconds).


• Time on site.


• Number of pages viewed.


• Scroll depth.


• Inactive period.


• Exit intent.

Combine a few conditions for better targeting. In this example, we’ll show the widget to new visitors who’ve spent at least 20 seconds on the page. You can also limit it to mobile users only, if that’s your focus.