Was recently in CF immigration doing a 90-day report and asked them the question.. was told only the main office near the airport deals with visa applications.. whether it's a new visa or extension 👍
Jumped through all these hoops myself.. non Thai marriage certificate has to be translated into Thai and stamped by MFA in Thailand.. but original also has to be stamped by embassy of country of marriage.. we used an agent in CM to handle it all.. so as to avoid having to fly down to Bankgkok ourselves.. they included a translated copy of my passport in case of need as well.. and was well worth the cost given the saving on flights etc.. one of the few occasions that agents really make sense imo.. process took around 2-3 weeks.. once documents are to hand marriage needs to be registered at your local Amphur and certificate of registration obtained.. I'd suggest you get 3-4 original stamped copies.. you need this to apply for a 'non-o' visa based on marriage.. you also need it to apply for a yellow book and a pink ID card later.. be aware some Amphurs try to retain your original stamped certificate of translation.. i told mine they could have it if they reimbursed me for the cost of it.. and they eventually backed down and took a copy they certified for themselves.. but it took some serious haggling to achieve that! Clearly different provinces and different amphurs have their own 'rules' but that's the gist of it.. good luck!
Simple solution mentioned many times here already.. but I'd check in to a hotel for 2 nights just before you intend to apply for your extension.. they will file a TM30 for you and usually do so on the day you check in.. ask them for a printed copy of the TM30 registration they do online.. then go to immigration the next day with it and apply for the extension.. then move to accommodation of choice for the rest of your stay.. provided you leave the country without any further interactions with immigration.. then a subsequent failure to do a TM30, (ie. by your next landlord) won't matter at all!
The married visa is a 'non-o' visa and he should apply for it in country.. generally speaking when he has 30 days left on his exemption stamp.. though some offices may stipulate waiting until 15 days unexpired.. there is no need to extend the initial stamp at all.. since the non-o process grants an initial 90-day stay (visa) which is then rolled into the 12-month non-o.. so it's possible to avoid the cost and bureaucracy of the
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day extension of stay by simply going straight for the non-o.. but it's essential to check out the specific requirements of the immigration office being used to get all your ducks in a row ahead of time.. you must have had your marriage registered at your local amphur and have a registration certificate.. best to get 3-4 copies properly stamped as originals.. and if you were married overseas (ie. outside of Thailand) that will necessitate having a translated copy of the marriage certificate properly notarized.. if you need to do this and live in the country where you were married then i suggest you get this done before you come to Thailand.. otherwise you'll need to engage an agent to do it for you once you're here.. since the process is very cumbersome.. especially if you are not living in Bangkok where most of the foreign embassies are located.. once marriage registered immediately apply for a yellow book at the local municipality.. this serves as proof of address for everything in Thailand and will make life much easier when applying for your visa (and at renewal) and when dealing with banks etc.. it also enables you to apply for the Pink ID card..which is akin to a farang national ID card albeit issued locally.. and is recognised by many institutions here.. such as the LTO when applying for (or renewing) your driving licence.. all these documents make interacting with immigration much easier.. imo, that's largely because you have demonstrated a real commitment to settling down and staying here permanently to support your Thai wife and family!
In CM it's a 30 second stop at the drive through kiosk at the main immigration office.. or alternatively go to the one at L2 Central Festival.. usually a 5 minute exercise!
So long as they haven't mis-spelt the names that do appear on your ticket it will be fine.. a spelling mis-match between passport and ticket is much more problematical!
Any form of contractual 'work' is forbidden without a work permit.. meaning where you are employed by a third party and earn a wage for your toil.. this extends to charity work where you will be labouring on a volunteer basis.. however, there is no law that prohibits you from undertaking routine maintenance on your own home.. or motor vehicle for that matter.. should you wish to do so.. judging by some of the comments here you'd think it was illegal to go out and buy your own groceries.. or even buy a take-away meal and return home to eat it.. because you should have had grab or deliveroo deliver it to keep thai's employed of course!
I'm a Brit married to a Thai and living in CM.. our local Amphur did not require a copy of my birth certificate to register my residence in the marital home.. but did require a translated (English into Thai) copy of our marriage certificate in order to issue a residence certificate.. which had to be certified by the embassy of the country of marriage and authenticated by the BOI.. we used an agent to expedite this process and thus avoid having to fly to Bangkok.. once i had that document i could present it to the office of the Municipality to obtain my 'yellow book'.. which has precluded the need to ever produce a residence certificate for any purpose thereafter.. every govt agency accepts the yellow book (or a copy alongside sight of the original) instead.. so no more visits to immigration for a residence certificate for the LTO etc.. and upon returning to the Amphur with it they were willing to issue me with a 'pink' ID card.. a laborious process but once completed it makes your life much easier.. especially when opening a bank account or applying for a driving license!
Despite this being a very genuine and reasonable 'excuse' to break the lease.. agents and landords will have very little sympathy.. and imo you should look to mitigate your losses.. that means planning your exit and effectively moving out prior to notifying the agent.. as others have advised here.. such that you do not risk having any personal items or possessions impounded because of your failure to pay the rent.. it's clearly better to lose a 2-month deposit than to pay another 8-months rent on an empty property.. and whilst the agent won't be too happy they will surely understand your reasoning.. any threats are futile because they will have no way of seeking legal redress once you have left the country.. and in any event it would not be economic to begin litigation for the sum involved.. and remember if they re-let the unit fairly quickly then this diminishes your liability.. because a landlord can only 'sue' for any actual losses incurred by you breaking the lease.. meaning if a new tenant is found and moves in after say 2-months of you vacating.. then he hasn't lost 8-months rent but only 2-months rent.. and could also seek compensation for any agents fees related to the re-letting.. less of course the deposit they are holding.. so the sum involved would be much smaller than you think and in all likelihood will be written off as irrecoverable.. and in all probability they would rather have the property occupied than unoccupied for the next 8-months.. from both a security and maintenance point of view.. immigration doesn't get involved in civil matters and should not be a concern when you leave or re-enter the country.. just do what you have to but don't make it more stressful for yourself by telling the agent until you have vacated the property.. you are breaking a legal contract to fulfil a moral contract and the latter is far more important imo.. and i doubt you will lose points for it when you are standing outside the 'pearly gates' one day!
The reality is that after 20 years of 'defrauding' as in your example.. a UK pensioner would be 87 years old already.. and in all probability wouldn't care less what the govt thought or did.. and there's every likelihood that such discriminatory rules will be repealed before then anyway.. the corrupticians that have been allowed to run the country for far too long are about to be exposed for the criminals they are!