How Shortened URLs Cause SMS Delivery Issues (and Fixes)

Shortened URLs save characters and enable click tracking, but public shorteners like bit.ly and rb.gy increasingly trigger carrier blocks. Knowing why and switching to branded short URLs protects your SMS delivery rates.

Why shortened URLs cause delivery issues

Multiple redirects

Public shorteners often redirect through several hops before landing on the destination. Carriers treat that pattern as suspicious because it can mask fraud.

No sender transparency

A bare bit.ly domain says nothing about who sent the link. That ambiguity raises filtering risk.

Carrier policies

• T-Mobile: Code of Conduct since September 1, 2020. Prefers a single recognizable domain tied to the business. Branded short URLs are acceptable. Prohibits URL cycling. Discourages multiple redirects.
• AT&T: Fully blocks public link shorteners due to fraud and phishing risk.

What this means for businesses

• Carriers are tightening rules to reduce spam, fraud, and abuse.
• Click tracking and link shortening get harder.
• Balance delivery success against tracking needs by adapting URL practices.

Three ways to improve SMS link delivery

1. Limit redirects

Each hop raises suspicion. Land users on the destination directly. Use UTM parameters for tracking instead of stacking redirect chains.

2. Use full-length URLs when space allows

Carriers prefer the full domain. The cost: it eats into the 160-character SMS budget. For critical links, accept the extra segment cost rather than risk a block.

3. Use a branded short URL

When space is tight, a branded short URL on your own domain (for example shop.yourbrand.com/promo) signals trust and matches carrier preferences. Custom domains for shortened URLs are usually cheaper than the cost of undelivered messages.

Key takeaway

You pay for every SMS you send, not just the ones that get delivered. Branded domains and clean redirect paths protect deliverability, brand trust, and the customer experience.