Lost contacts from Samsung A3

[Anonymous]

Periodically lose contacts from phone, in the past they come back after phone reboot but not this time. Looking on other forums this is quite common on certain Android phones, do not want to set phone back to factory settings as O2 Guro suggests as seem a bit extreme, especially as it keeps happening and is a known fault.

[MI5]

Where are you storing your contacts?
I keep all mine on Google so the phone is always in sync with my contacts list, that way, they won't get lost.

[jonsie]

Your contacts should automatically be backed up to Google. If you go into settings, accounts, Google and check just what syncs with the phone. Make sure contacts are synced by ticking the box. 

[MI5]

Other options you have with Android are alternative cloud storage options such as Outlook or an Exchange server or you can copy them all into phone storage.

[Anonymous]

Yes, my contacts are stored on Google and the phone backed up regularly.  Not ALL contacts dissapear, I get left with a few random ones which are different each time it happens.

[MI5]

Check here online to see if your list is complete https://contacts.google.com/
If so, it sounds like a sync problem.

[Anonymous]

Just checked via the link and the contact list is not complete, just showing the nine contacts that appear on my phone.

[MI5 · Accepted solution]

That's why you are losing them off phone then.
Somehow they are being deleted off the Google server.