You have a written canvas, a product or service you can actually deliver, and someone who says they are interested in buying. All that remains is to accept the first order. But at this point many business owners still do not know how to quote, how to ask for a deposit, which documents to give the customer, when the buyer will accept the work, and whether the work needs a licence. These problems are not hard, but if you do not prepare in advance, the first customer often becomes the one who teaches the most expensive lesson.
This guide follows the Business Model series: the Business Model Canvas, the Lean Canvas, choosing your first customer segment, testing that customers will really pay, working out the cost per sale, the money to prepare before opening a company and how B2B and B2C differ. Having worked through them to this point, this guide turns the canvas into a list of what you need before delivering work and taking your first payment.
The core answer
Before taking your first customer, have nine things in sequence: an offer that is clear about what you sell and what you do not sell; the scope of work and the acceptance criteria; a set of sales documents; a way of receiving money that is separate from your personal money; bookkeeping and record keeping from day one; any licence or registration relating to your product or service; handling of customer data and marketing; a check of the name and trademark; and a plan for following up after the sale. You do not need all nine to be perfect before the first sale, but you need to know which are required before selling and which can wait.
The rule (Thai law). The law relevant to the first customer is spread across several statutes. Deposits are in sections 377 and 378 of the Civil and Commercial Code. The seller's liability for defects is in section 472. An operator registered for value added tax must issue a tax invoice under section 86 of the Revenue Code. A person who must register commercially must comply with the Commercial Registration Act B.E. 2499. Partnerships and companies have a duty to keep accounts under the Accounting Act B.E. 2543. Electronic documents and signatures are valid under the Electronic Transactions Act B.E. 2544. And when selling to consumers, the Consumer Protection Act B.E. 2522 must be considered, as explained in the guide on how B2B and B2C differ.
Our practical view. Do not wait until everything is ready before selling, and do not sell first and look for the paperwork later. Treat the first sale as a controlled test. Keep the documents few but covering the risk points: scope of work, price, payment date, deposit and acceptance. Then improve after you have real data. What you genuinely must have before selling is any licence the law requires before you start, and a bank account for receiving money that is separate from your personal wallet.
The running example in this guide is hypothetical. Suppose a small sign and print design and production provider in Khon Kaen has a first customer, a restaurant, that asks for a quotation for a shop-front sign including installation. We will call the provider "the sign shop".
1. The offer: what you sell, what you do not, and how it is priced
A clear offer keeps both sides from understanding it differently. Write it so that it answers:
- What you sell. State the main items, specifications, quantity and what is included in the price.
- What you do not sell. State what is excluded, such as the fee for a permit to install the sign, revisions beyond the agreed number, or travel outside the service area.
- Price structure. Is it a lump sum or itemised? Does the price include or exclude value added tax (if you are registered)? This must be stated clearly.
- How long the offer lasts. A quotation should have an expiry date so that you are not held to an old price when costs change.
- Terms for changes. How will you charge if the customer asks to add, reduce or change the work?
In the guide on testing that customers will really pay you tested whether customers are willing to pay; here you write an offer that binds. Pricing worked out from costs is in the guide on cost per sale. If you sell a service, see more on pricing models in the guide to service pricing: fixed, hourly or monthly.
2. Scope of work, product specification and acceptance criteria
Most problems between sellers and customers come from what was not written down, not from what was written wrongly. A good scope of work has these elements:
| Topic | What to write |
|---|---|
| Deliverables | Items, sizes, materials, quantity, file formats, or the results the customer will get |
| What the customer must provide | Design, text, logo, site access, and the date by which the information is due |
| Timeline | Start date, delivery date, and the effect of delays from the customer's side |
| Revisions | The number of revisions allowed at no extra charge |
| Acceptance | Who inspects, what they inspect, within how many days, and whether silence counts as acceptance |
| Warranty | What is covered, for how long, and what is not covered |
Distinguishing whether you are selling goods or doing contract work has legal consequences. If it is a sale of existing or standard-made goods, the seller is liable for defects under section 472 of the Civil and Commercial Code. If it is a contract for work (จ้างทำของ), where the contractor completes the work and the client pays the price on completion, acceptance of the work and liability for defects fall under the chapter on contracts for work, which has different rules on handover, notice and limitation periods. A sign shop that designs a sign specially for this one customer may therefore be doing contract work, while a shop that sells ready-made signs is making a sale. You should state in the quotation which kind of work it is, and have a lawyer check the form of the documents if the job is of high value.
If your first customer is a large organisation that sends you its own contract, see the guide to checking a contract a large customer sends to an SME.
3. The set of sales documents
The minimum set of sales documents to prepare:
| Document | What it is for | Legal note |
|---|---|---|
| Quotation | Offers items, price, terms and the validity of the offer | State the issuer, date, recipient and payment terms |
| Order confirmation, or a short contract | Records that the customer agreed to the offer | Have the customer accept in writing, by email or chat is fine |
| Terms of sale | General terms, warranty, cancellation, returns | If selling to consumers, watch for unfair contract terms |
| Invoice | Requests payment as agreed | State the due date, transfer details and a reference number |
| Deposit receipt, or receipt | Proof the customer receives when they pay | Keep a copy, and issue it for what is actually received |
| Tax invoice | Only for those registered for value added tax | Must contain the items required by section 86/4 of the Revenue Code |
| Delivery note, or handover note | Confirms the delivery date and who received it | Have the customer sign; use it with the acceptance |
| Withholding tax certificate | A corporate customer that withholds tax must give it to the seller | Chase until you have all of them, to use as a tax credit |
Tax invoices. An operator registered for value added tax must prepare a tax invoice and a copy every time it sells goods or provides services, under section 86 of the Revenue Code, and hand it to the buyer. A person not yet registered should not issue a document that states it is a tax invoice. You should check with the Revenue Department or an accountant whether it is time to register. For receipts, check the Revenue Department's current forms and rules for your type of business.
Electronic documents. Sending quotations, invoices and confirmations by email or chat is valid, because section 7 of the Electronic Transactions Act B.E. 2544 provides that a message cannot be denied legal effect merely because it is in electronic form. For electronic signatures, see the details on signing contracts in the guide on electronic signatures in company contracts. The key points are to keep conversations and files so they can be retrieved, and to summarise the main terms in a single message for the customer to confirm.
Example order confirmation message (an example; adapt to the actual job)
Thank you for your order with the sign shop. Please confirm the details below.
1) Work: shop-front sign with installation, per the design sent by email on ____
2) Price: per quotation no. ____ (including/excluding VAT as stated in the quotation)
3) Payment: deposit as stated on confirmation, balance on delivery of the work
4) Delivery: within ____ working days from the date we receive the deposit and all the artwork files
5) Design revisions: ____ at no extra charge
6) Acceptance: the customer inspects within ____ days of delivery. If no defects are notified in writing within that period, the work is deemed accepted.
Please reply "confirm" to this message so that we can start work.
Deposits. Under section 377 of the Civil and Commercial Code, what is given on the day the contract is made is a deposit (มัดจำ), which is treated as evidence that the contract has been made and as security for performance, and section 378 sets the effect of a deposit when the debt is performed, when a party is in breach, or when performance becomes impossible: it counts as part payment, is forfeited or is returned, as provided. A seller should write on the receipt whether the payment is a "deposit" or an "advance payment" to match what is really intended, because the effects differ, and should state how it will be returned if the seller cannot deliver. If there is no company yet but you want to take a deposit in the name of a company about to be formed, see the guide on pre-incorporation contracts and promoter liability.
4. Getting paid: bank account, payment channels and records
- A separate bank account. If you are a company, you must use the company's account, because the company is a juristic person separate from its shareholders. If you are an individual, open a separate account for the business so the books are simpler and payment slips can be separated. Banks ask for different documents depending on the type of business, so ask the branch first.
- Payment channels. Bank transfer, PromptPay, cards or through a platform. Each channel has different fees and a different time before the money arrives. Choose the channel your target customers use, and include the fees in the cost per sale.
- Evidence of receipt. Keep the slip, the account statement entry and the invoice reference number together.
- Corporate customers. Ask the customer's accounting department when its payment run is, what documents it needs and whether you must register as a vendor. For preparing this, see the guide on how B2B and B2C differ.
- Money handling in the early stage. Do not use customers' money for personal purposes if it is company money, and do not use a customer's deposit to cover costs when you are not sure you will finish the customer's work.
For planning reserves and working capital before you start selling, see the guide to the money to prepare before opening a company.
5. Bookkeeping from day one
If you have a company or a registered ordinary partnership, you must keep accounts under the Accounting Act B.E. 2543, which is a duty of the bookkeeper and of the person responsible for keeping the accounts. Details for the first year are in the guide on what accounts to keep in the first year. Here we stress only what must start before the first sale.
- Keep every document from day one. Quotations, invoices, receipts, payment slips, delivery notes and withholding tax certificates.
- Name files and folders so they can be found again. For example by date and customer name.
- Separate personal money from business money. Whether you are a company or an individual.
- Send documents to the bookkeeper on the agreed cycle. Do not let them pile up until the end of the year.
- Ask the bookkeeper before the first sale what documents your sales must produce, whether there is withholding tax, and whether you have reached the threshold for VAT registration.
An individual business operator has personal income tax duties, which differ from a company's. You should consult an accountant on what records to keep and what returns to file, given your income.
6. Licences and business-specific requirements to check before selling
This item differs greatly by type of business, and it is often the one you should not postpone. You do not need to remember the full list, but you need to ask whether your business falls into any of the groups below.
| Type of business | What to check before selling |
|---|---|
| Food | Production site, product registration or notification, labels, under food law |
| Cosmetics | Notification of product details, labels and advertising claims |
| Health products, drugs, medical devices | Licence to produce, import or sell, and advertising restrictions |
| Education and tutoring schools | Permission to set up under the relevant laws |
| Transport and logistics | Transport operator licence and vehicle requirements |
| Financial services, lending, payment services | Licence or registration with the supervising agency |
| Online selling | Commercial registration, or registration under the direct sales and direct marketing law, in some forms |
| Restaurants, beauty salons, premises open to the public | Licence under public health or local laws, and site inspection |
| Companies with foreign shareholders | Restrictions under the law on foreign business operation |
Do not treat this table as complete; we wrote it only as starting questions. Fees, timelines and documents change with announcements, so check with the licensing agency or have a lawyer check first. See the services on business licences and FDA registration. If you sell goods that carry a label, see the guide to product labelling. Selling without a licence you are required to hold may lead to prosecution and an order to stop selling, which would cost you the first customer.
7. Customer data, marketing and website terms
As soon as you collect the name, phone number, address or purchase history of a customer who is an individual, you are collecting personal data, which falls under the Personal Data Protection Act B.E. 2562. What you should have from the first customer:
- A privacy notice saying what data you collect, for what purpose, for how long, and whom to contact. If you have a website or a form, the customer must see it before entering data.
- Consent for marketing. Send promotional messages only with a suitable lawful basis, which is often consent separate from the order.
- Terms of use for the website or app. If you sell online, you should have terms on ordering, payment, delivery, returns and contact channels.
- Keeping data secure. Do not give customer lists to others without a lawful basis.
For details see the PDPA checklist and the PDPA service.
8. Name and trademark
Before printing quotations, signs, business cards and posts, check the name and trademark first, because if the name is the same as or similar to a registered mark you may have to change it later, after customers know you. The minimum to do: search the trademark database of the Department of Intellectual Property, check the juristic person name at the Department of Business Development, and check the domain name and page name. For the application process see the guide on the trademark registration process and the trademark registration service.
9. After the first sale: feedback, warranty and follow-up
The first customer gives you more information than you expect. Do three things within a few weeks of delivery.
- Ask for feedback in writing. Ask what they liked, what they did not, and what they would say if they recommended you. If you want to use their comments or photos of the work in advertising, ask permission first.
- Handle the warranty. Record what the customer reports, fix it within the agreed time and keep evidence of the fix. The seller is liable for defects by law anyway under section 472 of the Civil and Commercial Code, and writing clear warranty terms helps you to perform them in practice.
- Collect the balance and complete the paperwork. Follow up the invoice, ask for the withholding tax certificate if there is one, and close the books on this job. If the customer does not pay on time, see the guide to unpaid invoices.
Then go back and review the canvas: which assumptions have been proved, which need to change, whether actual costs differ from what you calculated, and whether you are ready to move from an individual seller to a company. See the guide on when to move from an individual seller to a company.
10. Checklist before taking your first customer
Offer and scope
- Can write down what you sell and what is not included in the price
- The quotation states the price, payment terms and expiry date
- The scope of work states deliverables, timeline, number of revisions and acceptance criteria
- Know whether the job is a sale or a contract for work, and have written the terms to match
Documents and payment
- Have templates for the quotation, order confirmation, invoice, receipt and handover note
- If registered for value added tax, have a system for issuing correct tax invoices
- Have written the deposit and refund terms clearly
- Have a bank account for receiving money that is separate from personal money
- Have a vendor document pack for corporate customers
Accounting and tax
- Have talked to the bookkeeper about sales documents and withholding tax
- Have a folder for keeping records from day one
- Have checked whether you must register commercially, and whether being an individual or a company suits this customer
Licences and specific requirements
- Have checked whether the product or service needs a licence or registration before sale
- Have checked labels and advertising claims
Data, name and after-sale
- Have a privacy notice and a way to obtain marketing consent
- Have checked the name, trademark and domain name
- Have a plan to ask for feedback and handle after-sale matters within a set period
Further reading
- How B2B and B2C differ: before preparing documents to suit the customer type
- Working out cost per sale before opening a company: check that the quoted price leaves a real profit
- Money to prepare before opening a company: registered capital, start-up funds and working capital
- What accounts to keep in the first year: accounting details after opening a company
- Pre-incorporation contracts and promoter liability: when you take a deposit before the company exists
- When to move from an individual seller to a company: deciding on the form of the business
- Trademark registration process: before using the name with real customers
The first customer should be a controlled test. So know before you start what you are selling to whom, at what price and on what terms, how you will be paid, and whether you hold every licence you need.
We help review and prepare quotations, contracts and terms of sale to suit your business, check which licences your product or service needs before you start selling, and set up a document system that supports bookkeeping and tax. For an initial consultation, call +66 92 254 2045 or send us the details. See also business licences and contracts and business documents.
This guide is published by Suwanvara Law Firm — a Khon Kaen law firm established in 1986. General information only, not legal advice on a specific matter.
