I typed +966 0501234567 and the tool accepted it, so why does the link not reach my chat?

What actually went wrong

Saudi mobiles are written locally as 0501234567. That first 0 is the domestic trunk prefix and it only matters for calls inside the country. Once you add the country code it has to go. Many people type +966 and then paste the number exactly as it sits in their contacts, which gives:

https://wa.me/9660501234567

That is an example number, not a real one. Count the digits: 13 instead of 12. The link still opens WhatsApp, but it points at a number that is not the one your account uses, so the customer never reaches you.

Why the tool did not object

The WhatsApp link generator checks format only. It has no table of how long numbers are in each country. Its rules are simple: after stripping spaces and a leading + or 00, the number must be digits only, must not start with 0, and must have 8 to 15 digits. 9660501234567 starts with 9 and has 13 digits, so it passes all three. A stray 0 in the middle is invisible to any general check.

Type 0501234567 on its own and the tool rejects it straight away with a message saying the number starts with 0. The problem only appears when the country code and the local 0 end up together.

Two ways to fix it

1. Easiest: pick +966 Saudi Arabia in the country-code helper, then type the local number 0501234567 the way you usually write it. The tool removes one leading 0 and adds 966, giving 966501234567.
2. Or leave the helper on 'The number I type includes the country code' and type the full number with the 0 already removed: +966 50 123 4567.
3. Either way, read the 'Number inside the link' line under the result. It shows the final number with a + in front.
4. Press 'Open link' and check that the chat that appears is your own account.

A sign that catches it before you publish

When you use the helper and type a number that begins with 0, a note appears next to the result: '(the leading 0 of the local number was removed)'. That note tells you the tool dealt with the 0. If you type the full number yourself there is no note, so count instead: a Saudi mobile in international form has 12 digits and starts 9665. If you see 96605 at the start, there is an extra 0.

This is not only a Saudi issue. The UAE, Egypt and the UK also use a local 0 that must be dropped, and you fall into the same trap there if you type the country code followed by the full local number.