2026-04-20 · TWH Team

B2B Maintenance Invoices and Withholding Tax (WHT) in Thailand: FAQ

Common questions about VAT-registered invoices, 3% withholding tax, and documentation for B2B maintenance work in Thailand.

If you are a property manager, operations director, or procurement officer managing B2B maintenance contracts in Thailand, you will encounter a set of recurring tax and invoicing questions. Getting these wrong creates problems at audit time — Revenue Department scrutiny, disallowed expense deductions, and friction with vendors who may not understand their own obligations.

This FAQ covers the most common questions we hear from clients managing maintenance spend in Thailand.

Frequently Asked Questions

Q1: Does every maintenance vendor need to issue a formal tax invoice?

Only VAT-registered vendors are required to issue a full tax invoice (ใบกำกับภาษี). A vendor registered for VAT must issue a tax invoice for every sale or service rendered. If the vendor is not VAT-registered — which is legal for businesses with annual revenue below THB 1.8 million — they issue a regular receipt (ใบเสร็จรับเงิน) instead.

For your accounting team, the distinction matters: only a proper tax invoice from a VAT-registered entity entitles your company to claim VAT input credit. If you pay a non-VAT vendor, you cannot reclaim the VAT — but there is no VAT charged in the first place.

Practical implication: For significant recurring maintenance contracts, prefer VAT-registered vendors. Their invoices give you the paper trail needed for both VAT returns and corporate income tax deductions.

Q2: What is the VAT registration threshold in Thailand?

The threshold is THB 1.8 million in annual revenue. Businesses below this threshold are exempt from VAT registration, though they may voluntarily register. Businesses above THB 1.8 million must register and charge 7% VAT on all taxable supplies.

For maintenance work, most professional contractors — cleaning companies, electrical contractors, AC service firms — operating at a scale relevant to B2B clients will be VAT-registered. However, sole-trader technicians and small subcontractors often are not.

Q3: What is withholding tax (WHT), and when does it apply to maintenance payments?

Withholding tax (ภาษีหัก ณ ที่จ่าย) is a mechanism where the payer deducts a percentage of the payment and remits it directly to the Revenue Department on behalf of the recipient. It is not an additional cost — it is a prepayment of the vendor’s income tax obligation.

For maintenance and repair services paid to a juristic person (company or registered partnership), the withholding tax rate is 3%.

Example: You owe a maintenance contractor THB 10,000 for a job. You pay THB 9,700 and remit THB 300 to the Revenue Department. You issue the vendor a withholding tax certificate (หนังสือรับรองการหักภาษี ณ ที่จ่าย) as evidence of the deduction.

Q4: Does WHT apply when paying individual technicians (natural persons)?

Yes, but at a different rate. Payments to individual persons for service work fall under Section 40(2) of the Revenue Code — income from employment or services — and are withheld at a progressive rate, or a flat 3% for independent contractors if the payment exceeds THB 1,000 per transaction.

In practice, most B2B property managers avoid contracting directly with individuals for this reason. Contracting with a registered company simplifies compliance: one rate (3%), one form (PND 53), and clear corporate liability.

Q5: What fields must appear on a valid Thai tax invoice?

A tax invoice must contain all of the following:

• The words “ใบกำกับภาษี” (Tax Invoice) prominently displayed
• Vendor’s legal company name and address
• Vendor’s 13-digit Tax Identification Number (TIN)
• Sequential invoice number
• Date of issue
• Description of goods or services
• Quantity and unit price
• Total amount before VAT
• VAT amount (7%)
• Grand total including VAT
• Your company’s name and address (the buyer)

Missing any of these fields — particularly the TIN or the buyer’s name — can disqualify the invoice for input VAT credit claims and complicate expense deduction at corporate tax time.

Q6: What is the withholding tax certificate (หนังสือรับรองการหักภาษี ณ ที่จ่าย), and when must I issue it?

The withholding tax certificate is the document you (as the payer) issue to the vendor confirming that WHT was deducted. It must be issued at the time of payment. The vendor uses it as evidence when filing their own annual corporate income tax return.

Required fields on the certificate:

• Your company’s name, address, and TIN (as payer)
• Vendor’s name, address, and TIN (as recipient)
• Type of income (e.g., “service fees” — Section 40(8))
• Payment date
• Gross amount before WHT
• WHT rate and amount withheld
• Signature of authorised signatory

Many accounting systems (ERPs, QuickBooks Thailand localisation, SAP) can generate this automatically if set up correctly.

Q7: What is PND 53, and when must it be filed?

PND 53 (ภ.ง.ด. 53) is the monthly withholding tax remittance form for payments made to juristic persons. If you made any maintenance payments with WHT deductions during the month, you must:

1. Remit the withheld amount to the Revenue Department within 7 days of the following month (e.g., payments in March → file by April 7)
2. File the PND 53 form either at your local Revenue Department office or via the e-Filing portal at rd.go.th

If the filing deadline falls on a public holiday, it extends to the next working day. Late filing incurs a 1.5% per month surcharge on the outstanding amount.

Important: Many small companies mistakenly believe WHT is only filed quarterly. For payments to juristic persons, PND 53 is a monthly obligation whenever payments with WHT deductions occurred in that month.

Q8: Can I aggregate multiple vendor payments into one PND 53 filing?

Yes. PND 53 is a summary form — you list all juristic person payees for the month on a single form with one total remittance. There is no requirement to file a separate PND 53 per vendor. This is one reason why consolidating maintenance vendors (fewer vendors, fewer line items) reduces finance processing time significantly.

Q9: Our vendor refuses to issue a proper tax invoice. What are our options?

This is more common with small subcontractors and sole traders. Your options:

1. Replace the vendor with a VAT-registered company — for recurring B2B maintenance contracts, this is the cleanest solution
2. Accept a receipt (ใบเสร็จ) without VAT — you lose input VAT credit but can still deduct the expense for corporate tax if you have the receipt and a bank transfer record
3. Use a platform or agency that consolidates vendor work and issues compliant invoices from their own entity — this is the model used by B2B maintenance platforms

For clients managing multiple properties or locations, working through a platform that handles all vendor relationships and issues a single consolidated tax invoice each month eliminates this problem entirely. See our vendor network for how TWH handles invoicing on behalf of verified vendors.

Q10: We pay via bank transfer. Do we still need physical WHT certificates?

Yes. Bank transfer records prove the payment occurred, but they do not fulfill the statutory obligation to issue a withholding tax certificate. The certificate is a separate legal document that must accompany or closely follow the payment.

Digital copies are acceptable for your own records and increasingly accepted at audit. However, many vendors still expect a printed certificate with an official stamp. Best practice: issue the certificate promptly (within 1–3 days of payment), keep a copy in your accounting system, and send the original to the vendor.

If using an accounting platform that integrates with Thailand’s e-WHT system (available via the Revenue Department’s e-filing portal), digital certificates are legally equivalent to paper originals.

Summary Table

Topic	Key Rule
VAT registration threshold	THB 1.8M annual revenue
VAT rate	7%
WHT rate for maintenance services (juristic)	3%
WHT filing form	PND 53
Filing deadline	Within 7 days of following month
Withholding tax certificate	Must be issued at time of payment
Required invoice fields	TIN, company names, sequential number, VAT breakdown

Keeping Compliance Simple

For property managers and operations teams handling 20–100+ maintenance jobs per month, manual WHT processing across many vendors creates material compliance risk and administrative burden. The most effective approaches are:

1. Consolidate to fewer, larger vendors with proper VAT registration
2. Use a B2B maintenance platform that issues consolidated monthly invoices and handles vendor-level WHT documentation
3. Ensure your accounting software is configured for Thai WHT rules from day one

For questions specific to your property or operational setup, the TWH maintenance network works exclusively with VAT-registered vendors and provides clients with complete, audit-ready documentation for every job.