Monthly accounting and tax for small and mid-size companies

Small and mid-size Thai companies usually start out with the owner doing the books alone or leaving it to a general staff member. Once sales grow past a few hundred transactions a month, that old routine stops keeping up, because company accounting is never just recording income and expense — it is tied to several tax obligations at once every month, from VAT to withholding tax to social security. A slip in any one of them does not stay contained to that month; it carries forward into the annual financial statements that must pass audit.

The point many businesses overlook is that filing on time and having correct books are not the same thing. A company can file PP30 punctually every month using the invoices at hand, yet without regular reconciliation against the general ledger and bank statements, the filed figures may not match the year-end statements. When the auditor arrives, hours go into tracing the discrepancy back across the whole year — work that regular monthly bookkeeping would have prevented from the start.

Hiring an in-house accountant carries hidden costs beyond salary — keeping up with tax rules that change nearly every year, the risk of a sudden resignation leaving no one to continue the work, and having no second person to check quality. For a business with five to fifty staff, an outside team that reviews its own output before it reaches the owner usually reduces this exposure more than relying on a single employee ever could.

Payroll is another area SMEs tend to underestimate, since on the surface it looks like multiplying a rate by days worked. In practice it means computing withholding tax on a progressive scale, applying allowances that differ from one employee to the next, capping social security contributions at the statutory ceiling, and remitting everything on schedule without compounding errors. When staff turnover follows the business's seasonal cycle, this complexity only grows and becomes a burden a small HR function struggles to absorb.

Corporate tax planning is another area often left as a surprise at closing time, even though a running profit and loss estimate can be built from the bookkeeping data already on file. Knowing the tax trend early lets an owner time asset purchases, staff bonuses or cash reserves sensibly, instead of scrambling for a lump sum exactly when the business needs its working capital elsewhere — a situation common among companies with no continuous number tracking.

Annual audit is a legal duty for every registered company in Thailand, regardless of size, requiring a licensed auditor to sign off before filing with the DBD. What decides whether that audit runs smoothly or drags on is the quality of the books built up across the year. Complete documents with continuous reconciliation let the auditor move faster and usually keep the audit cost lower, while books that accumulate problems all year stretch the process out well beyond what it should take.

For a business expanding its team or opening new branches, an accounting system set up early keeps growth from stumbling, because every branch or sub-unit must feed data into the same system in the same format. Relying on separate manual methods per location turns month-end consolidation into a major task, and the risk of data slipping through the cracks rises with each added branch. Standardising documents and submission cycles early is worth far more than fixing the mess later.

In the end, the question an SME owner should ask is not simply who will do the books, but who will make the business clear enough to decide on every month. Good accounting is never only paperwork for the tax office — it is the tool that shows which product line actually turns a profit, which cost is creeping up, and whether the company holds enough cash for its expansion plans. Choosing an accounting team should look past punctual filing toward how continuously that team keeps the whole picture in view.

Many SMEs still hand petty cash to purchasing staff for on-the-spot spending without a tight control process. At month-end, the accounting team ends up chasing receipts submitted one at a time, some missing required details, some lost along the way, leaving the petty cash float never quite matching what actually gets recorded. This looks minor short-term but compounds into a gap auditors flag every year, since a cash fund with no clear approval step opens the door to duplicate claims or unrelated spending slipping through unnoticed. The workable fix is a defined per-claim limit, a mandatory approval slip before any payout, and a weekly clearing cycle for the petty cash account instead of letting it pile up until month-end review.

Many owners assume dividends can go out the moment retained earnings appear on the balance sheet, without realizing the law requires setting aside the statutory reserve and holding a shareholder meeting to approve the payout before it happens. Skipping that step risks the payment being reclassified as a shareholder loan instead, carrying entirely different tax consequences, particularly around interest the Revenue Department may impute if none was charged at a market rate. A company paying dividends to individual shareholders also has to withhold at the statutory rate and remit it correctly, a step many businesses overlook because they treat it as a private matter between the company and its owners. Planning the dividend process correctly from the start heads off problems that would otherwise surface later.

For a business that imports goods occasionally, whether for internal use or resale, the correct import cost must roll in the purchase price, international freight, insurance, import duty and the VAT paid at customs — all capitalized into inventory cost rather than expensed in the period the cash goes out. Getting this wrong understates inventory cost and overstates the gross margin shown on the statements. Businesses that import infrequently and never build a standard process are especially prone to miscalculating each time a new shipment arrives. Setting a clear procedure from the very first import, along with a cost-summary template tied to each customs declaration, keeps the inventory figure accurate whether shipments arrive often or only occasionally.