What is the 90-day reporting requirement for visa holders in Thailand?

It is infamous (as in a bit of a pain in the arse, and a bit silly buy typical Thai bureaucracy in action) but pretty straightforward process. It will not have been on your visa documentation as it is not vis specific - it applies to any foreigner staying in Thailand for 90 day or more and has to be done at least every 90 days you are there. You have to go to an IO (Immigration Office) with your passport and some evidence of where you are staying (rent agreement etc - but IO's can vary a little in what docs they actually require so worth visiting to get their specific reqs ahead). You will then get a little slip of paper that they staple to you passport, and you keep that there until your next 90 days. After you have done your first one, you can do later ones online. There is another process called TM30 which is where your residence is reported to Immigration upon your arrival (has to be done within 24 hrs - at least in theory). This is supposed to be a landlord's responsibility, but whilst hotels and large resorts almost always do it, smaller resorts, individual lettings and AirBnB places generally do not, and I am afraid, as unfair as it sounds some of them simply won't do it and you have to do it instead as all the IO's will refuse to do any process for you unless you have an up to date TM30. I am happy to help advise you on any of this if you want any more info or guidance - just DM me.

There is nothing written about the DTV needing a 90 day report, its a 180 day multi entry visa, I've read this, but there is nothing from the authorities to suggest it.

Can you do it at any office or only where you reside?

Can you not do it online the first time? And how many days prior to 90 can it be done?

After your first report you can do online in 2 minutes

Fill it once at the immigration after that online here

Takes less then 5 min

You must file a TM30 with Immigration within 24hrs of arrival in Thailand. Then every continual stay of 90 days requires you to file a TM47.

Easy to do . Bring your passport rm30 and fill a form out

Super simple. Go to immigration, fill out the form, get a slip of paper to prove it's done.

It's normal on almost all visas that you have to report to immigration every 90 consecutive days that you are inside Thailand. If you leave Thailand part way into the 90 days it is reset and you start counting again from the day you reenter the country

I hawe a non imig 0 and need to visite imigration ewery 3 mnth

Have to!