CAA-assisted ITIN service

Get your U.S. ITIN without the paperwork headache

TinTax prepares and files your IRS Individual Taxpayer Identification Number application. Pay securely, share your details once, and we handle the rest.

Encrypted, private storage Guided bilingual form Instant payment verification

How it works

1

Choose your service

Pick the ITIN service that fits your situation and pay securely by PromptPay or bank transfer.

2

Verify your payment

Upload your payment slip. We confirm it automatically — usually in seconds.

3

Share your information

Fill in one guided form and upload your documents. Everything is encrypted and private.

4

We prepare your ITIN

Our team reviews everything and files your application with the IRS, keeping you updated on LINE.

Choose your service

Transparent pricing. No hidden fees.

New ITIN (previously rejected)
For applicants whose earlier ITIN application was not successful.
Contact us
  • Review of your previous rejection
  • Corrected Form W-7 preparation
  • Re-filing with the IRS
  • Priority handling & LINE updates
Contact support
Renew or update an ITIN
For applicants who already have an ITIN and need to renew or update it.
THB 3,900
  • Renewal / update preparation
  • Document review by our team
  • Filing with the IRS
  • Updates via LINE
Select

Frequently asked questions

What is an ITIN?

An Individual Taxpayer Identification Number (ITIN) is a tax-processing number issued by the U.S. IRS for people who need a U.S. taxpayer number but are not eligible for a Social Security Number.

How long does it take?

Once we file with the IRS, processing typically takes several weeks. We keep you updated at every step.

Is my personal information safe?

Yes. Your data and documents are stored encrypted on our own systems, are never shared for marketing, and are used only to prepare your ITIN application.

Which documents will I need?

Usually a passport. If you don't have one, other government IDs may work but carry a higher chance of IRS rejection. The form guides you based on your answers.