A work permit is not a document you obtain once. It is a matched set of employer conditions, visa category and job description that has to stay consistent every year.

Foreign nationals are refused work permits far more often because of their employer than because of themselves. The labour office looks first at the company: is the registered capital paid up, is there an office it can inspect, are social security contributions being filed for the Thai staff who make up the required ratio, and does the company's registered objective actually cover the work the foreigner will do. A company whose accounts show four employees on paper but three contribution filings has failed before the application is read.

The ratio rule in practice means four Thai employees for each foreign worker, and two million baht of paid-up capital for each foreign position. Exemptions exist and matter: promoted companies under the Board of Investment, representative offices, and certain treaty positions operate on different arithmetic. Choosing the wrong track wastes a month.

The job description is the part clients treat casually and officers treat literally. The permit lists duties, and work outside those duties is unpermitted work even when it is obviously part of running the business. We write the description broadly enough to reflect the real role and narrowly enough to stay within the reserved-occupation restrictions in Thai law.

The correct order is visa first, permit second. The Non-Immigrant B visa is applied for at a Thai embassy or consulate abroad, or converted inside Thailand from a qualifying entry where the immigration office permits it. Attempting the reverse, or entering on a tourist stamp and hoping to convert, is the most common reason a start date slips by six weeks.

Once the permit is issued, three separate calendars begin and none of them reminds you. The permit itself has an expiry. The visa extension has a different expiry and is granted by the immigration office on evidence of continuing employment, tax payment and company standing. Ninety-day reporting runs independently of both. Missing the ninety-day report attracts a fine; missing a visa extension by a single day means leaving the country and starting again.

Renewal is an annual audit of the employment relationship. Immigration and labour officers ask for withholding tax certificates showing the salary actually paid, social security filings, the company's audited statements and evidence the Thai headcount ratio is still satisfied. A salary declared for the permit but not paid through payroll is the discrepancy that ends renewals.

Dependent visas for a spouse and children under twenty are granted on the strength of the primary holder's status, with legalised marriage and birth certificates. They do not carry the right to work; a spouse who wants to work needs an application in their own right, supported by the employer's own qualification.

Changing employer means a new permit, not a transfer. Resigning before the new permit is in place cancels the basis of the visa extension, and the grace period is short. We overlap the two processes wherever the outgoing employer will cooperate, and we tell you plainly when they will not.

Moving office, changing job title, adding a branch or amending the company's objectives all require the permit to be updated. These amendments are inexpensive and quick when done at the time, and they are the first thing an inspector compares against reality.