Common mistakes

2 min read · Chapter 9 of 10

What usually goes wrong

Symptom	Likely cause	First thing to check
Every 10DLC message fails	Number not on an approved campaign, or campaign not yet provisioned at that carrier	The number's campaign link and per-carrier campaign status
Messages accepted but never arrive	Carrier filtering: content unlike registered samples, public URL shortener, volume spike, traffic spread across numbers	Delivery rate by carrier, then content against the samples
T-Mobile traffic stops mid-afternoon	The brand's daily cap is used up (shared by all its campaigns)	The brand's vet score and daily volume at T-Mobile
Toll-free messages blocked	Number not verified, or verification rejected (missing business registration number, weak opt-in proof)	Verification status and reason
OTP spend spikes with no new sign-ups	SMS pumping	Conversion by destination country and number prefix
Brand name abroad arrives as a random number	Alpha not supported (Colombia, Argentina, Chile) or not registered (Mexico)	The country's alpha pattern; where alpha won't survive, use a local short code or WhatsApp
"Likely-SCAM" in Singapore, "Unverified" in Australia, nothing at all in Spain	Sender missing from the national registry, or (Spain) a provider in the route not enabled	Registry status for that country and route
WhatsApp free-form reply rejected	The 24-hour customer service window has closed	Time of the user's last message; send an approved template
WhatsApp utility template billed as marketing	Meta recategorized it	The category-change webhook; request review within 60 days
WhatsApp marketing to US numbers never delivers	Meta currently doesn't deliver marketing templates to +1 numbers	Recipient country code; use SMS or RCS for US marketing
RCS works on Android but not iPhone, or returns 404	Agent not launched on that carrier, carrier hasn't enabled business RCS on iOS, or the user's toggle is off	Per-carrier launch status; run a capability check before sending
Port rejected	Mismatch with the losing carrier's customer service record (service address, name, account number, PIN)	Pull the record (the CSR) before submitting and match it exactly
Outbound calls labelled "Spam Likely" or blocked	B or C attestation, bursts of short calls, number cycling, no reputation yet	Attestation level, FreeCallerRegistry registration, SIP 603+ responses
911 call reaches the wrong PSAP	Address never validated, nomadic user moved, stale record after a port	The number's 911 record and when it was last validated