Your WhatsApp messages usually don’t deliver (stuck on one grey tick, or “sending” forever) because something is blocking the path between you , WhatsApp’s servers, and the other person’s phone.

Main reasons your messages aren’t delivering

  1. Your internet is weak or off
    • Wi‑Fi is unstable, mobile data is off, or you’re in a low-signal area.
 * WhatsApp can’t send the message to its servers, so it shows a clock icon or stays on “sending.”
  1. Their phone is offline or inactive
    • Their phone is off, in airplane mode, has no data, or they haven’t opened WhatsApp in a long time.
 * Messages reach WhatsApp (one grey tick) but not their device, so they never turn into double ticks.
  1. You’ve been blocked (or muted in some business setups)
    • If someone blocks you, messages will stay on one grey tick forever, even if they’re online and active with others.
 * There’s no “you’re blocked” warning; you just see permanent non‑delivery to that contact.
  1. Wrong or inactive number / not on WhatsApp
    • The number is typed wrong, the person changed numbers, or it’s a landline/VoIP that doesn’t support WhatsApp.
 * For that contact, messages never deliver and may show errors in business tools or analytics.
  1. Country or policy restrictions (less common)
    • Some countries or carriers restrict certain WhatsApp traffic, which can randomly block delivery.
 * You might see good delivery to some regions but constant single ticks to others in your list.
  1. Using unofficial or “hacked” WhatsApp tools
    • Third‑party bulk senders, browser extensions, or modded apps can cause bans or silent delivery failures.
 * Symptoms include random non‑delivery, logouts, or your number being temporarily/permanently banned.
  1. Business / API limits, templates, and opt‑in issues (if you’re using WhatsApp Business with a platform)
    • Messages may fail if:
      • You message people who never gave WhatsApp opt‑in.
   * Your message template is unapproved, paused, or considered low quality/spammy.

   * You exceed WhatsApp’s messaging/broadcast limits or violate the 24‑hour reply window.

Quick step‑by‑step checklist (for normal users)

  1. Check your own internet
    • Open a browser or another app (YouTube, Instagram) to see if anything loads properly.
 * Toggle airplane mode on/off, then switch between Wi‑Fi and mobile data and try again.
  1. Restart things
    • Restart your phone, then reopen WhatsApp.
 * If you use VPN or firewall apps, turn them off temporarily and re‑test.
  1. Update & re‑login
    • Update WhatsApp from the official app store.
 * If issues persist only on your account, log out of WhatsApp Web or linked devices and try from your phone alone.
  1. Test with different contacts
    • Send a message to 2–3 other people.
    • If others show double ticks but one person stays on single tick, the problem is likely on their side or you might be blocked.
  1. Suspect blocking for just one person
    • Signs it might be a block (not 100% proof):
      • Only that contact never goes past one grey tick over several messages and days.
   * Their profile picture and last seen/online status disappeared if you used to see them (when privacy allows).

 * There’s nothing technical you can do to “force” delivery if you’re blocked.

If you’re a WhatsApp Business / marketing user

If your question “why are my WhatsApp messages not delivering” is about campaigns or broadcasts , reasons are a bit more technical:

  • Invalid or outdated contact list : Lots of numbers are wrong, inactive, or not on WhatsApp.
  • No opt‑in / spammy content : People block or report you, and WhatsApp lowers your quality rating.
  • Template or limit issues :
    • Templates marked low quality, paused, or disabled.
* Portfolio‑wide messaging limits hit (since late 2025), causing sudden delivery drops.

What to do next (business side):

  • Clean your list (remove bounced/invalid numbers, long‑inactive contacts).
  • Use clear, non‑spammy templates, add value, and get explicit opt‑in.
  • Check your analytics/error codes to see if failures cluster around certain templates, countries, or campaigns.

Mini example: one friend vs. everyone

You message Friend A, B, and C.
A and B show double ticks in seconds, but C stays on one grey tick for days.
Your internet is fine and other chats work.
Most likely, Friend C’s phone is offline for a long time or they’ve blocked you.

TL;DR:

  • If no one gets your messages: it’s almost always your internet, device, or app.
  • If only some people don’t get them: it’s usually their phone being offline, a wrong number, regional issues, or you being blocked.
  • If you’re doing broadcasts/marketing : think invalid numbers, missing opt‑in, poor template quality, or hitting WhatsApp’s sending limits.

Information gathered from public forums or data available on the internet and portrayed here.