Public URL shorteners are heavily abused by phishing syndicates; carrier spam filters automatically block messages containing shared bit.ly links.
When developers need to include links in SMS messages, they frequently reach for public URL shorteners to conserve character counts. However, including links from shared shortener domains (like bit.ly or tinyurl.com) is the single fastest way to guarantee 100% carrier delivery failure.
1 Why Public Shorteners Are Blocked
Because public shortener domains are shared by millions of users, malicious phishing campaigns routinely abuse them. Mobile network operators maintain blacklists of public shortener domains. When an incoming SMS contains a domain from this blacklist, carrier firewalls discard it immediately.
2 The Branded Short Domain Solution
To safely send links in commercial SMS:
1. Provision a dedicated branded domain (e.g. smsr.vr or go.company.com).
2. Register the domain explicitly in your A2P 10DLC campaign submission.
3. Ensure the domain has valid SSL and redirects cleanly to your canonical web property.
Frequently Asked Questions • Carrier Spam Filters & Deliverability
Yes. Full canonical URLs on your primary corporate domain (e.g. https://company.com/verify) pass carrier spam filters cleanly without reputation issues.