Cash raised from the transaction will be used to pay off tax arrears. To balance those responsibilities, you do have certain rights as a taxpayer. You have many rights under the law and I think it is important that you know your rights. I have taken the most up-to-date information from the website of the Revenue Department (www.rd.go.th) to share it here with you, (along with my own comments that may be useful to you). 

1) Tax installment payment: For personal income tax, a taxpayer can pay any tax amount which exceeds 3000 baht in up to three installments without paying fines or surcharges. A taxpayer can file a request for an installment payment of tax arrears. However, such payment must meet the requirements set by the Revenue Department 
Comment: Besides personal income tax, basically the tax officer also uses the same rule for other kinds of tax. 

 

2) Appeal in dispute of tax assessment: In the case where a taxpayer disagrees with the decision made by the assessment officer, he has the right to appeal to the Commission of Appeals (in the form P.S.6) within 30 days starting from the day when an assessment notice has been received. Should a taxpayer disagree with the ruling of the Commission of Appeals, he has the right to appeal within 30 days starting from the day the ruling of the Commission of Appeals has been received. Should you fail to appeal within 30 days, you no longer have the right to appeal and must pay the whole amount of tax, fine and surcharge. 

3) Deferral of tax payment by using collateral for tax arrears: The right to appeal is not a deferral of tax payment. A taxpayer who receives a tax assessment notice must pay tax on time as stated in the assessment notice. However, should you wish to wait for the hearing or decision of the Commission of Appeals, you have the right to defer tax payment by providing various securities as collateral in accordance with the rules and regulations of the Revenue Department. 

Comment: You have the right to wait until getting the result of your appeal but remember that if the result is not what you want, you have to pay interest of 1.5% per month for the delay of payment on tax and penalty. 

4) Application for exemption or reduction of fine and surcharge: A taxpayer has the duty to file their tax return and pay the proper taxes on time. Should you fail to do so, you will be subject to a fine and surcharge on top of the tax due. However, on some special grounds you may request for an exemption or reduction of fine. A tax officer does not have the power under any law to exempt or reduce surcharge. Only in the case where the Director-General grants an extension of the time period of tax payment or remittance and such tax has been paid or remitted within the extended time period, then the surcharge may be reduced to 50% thereof. 
Comment: Generally, the district tax office can give up to 50% reduction for the fine but you have to request the reduction in writing. Within the request letter there are certain specific sentences that are required in order to get a reduction, as follows; - That your policy is to comply to the laws - That the mistake you have made is not intentional but due to lack of understanding of the laws. - That you have provided good cooperation and assisted the tax officers in acquiring additional documents or information during the audit period 
5) Access to documents: A taxpayer has the right to make a copy of his documents relevant to his past tax payment record (tax returns and receipt). 

Comment: This means, you can go to the tax office in your area to ask for a certified copy of your tax return form that you have filed in the past, for which you may be charged a small fee.