US K-2 and K-4 Visa
K-2 visas cover unmarried children under 21 of a K-1 fiancé beneficiary; K-4 covers children of a K-3 spouse beneficiary. Each child requires a separate DS-160, medical exam, and Embassy Bangkok processing with custody consent where applicable.
Children must be listed on the parent's USCIS petition from the start. Thai birth certificates need certified English translations. Thai Visa Centre helps K-1 families prepare coordinated document packs for the full family group before embassy interviews.
Separate DS-160 for each child
Linked to parent's K-3 case
Derivative interviews with parent
Same visa validity rules apply
Who qualifies?
Unmarried children under 21 of a K-1 or K-3 beneficiary may qualify as K-2 or K-4 derivatives when listed on the parent's approved petition with complete relationship documentation.
- Parent holds approved K-1 or K-3 petition
- Child unmarried and under 21 at time of visa issuance
- Child listed on parent's I-129F or K-3 petition
- Valid passport and birth certificate showing relationship
- Medical exam completed for each derivative applicant
- Certified English translation of Thai birth certificate
Important: TVC prepares documents and checklists. You lodge through official USCIS and State Department channels. Each child needs a separate DS-160. Final decisions rest with the consular officer.
US visa journey stages
K-2 and K-4 cases follow the parent's petition approval, then separate DS-160 filings, medical exams, and coordinated Embassy Bangkok interviews for each child.
| Stage | Action | Outcome |
|---|---|---|
| Petition stage | Children listed on I-129F | USCIS approves as derivatives |
| Embassy prep | DS-160 and medical per child | Documents gathered in Bangkok |
| Interview | Parent and children at Bangkok | Relationship verified via birth certificates |
| US entry | Travel on K-2 or K-4 | Follow parent's adjustment path |
Application process from Thailand
Follow this sequence when preparing K-2 or K-4 derivative applications from Bangkok.
| Step | Action |
|---|---|
| 1 | Include eligible children on parent's I-129F or K-3 petition |
| 2 | File separate DS-160 for each child when embassy instructs |
| 3 | Complete medical exam with panel physician for each child |
| 4 | Gather birth certificates with certified English translations |
| 5 | Attend Embassy Bangkok interview with complete family file |
| 6 | Enter US on K-2 or K-4 and follow parent's status rules |
List children on parent petition
Include all eligible unmarried children under 21 on the parent's Form I-129F for K-1 cases or K-3 petition. Children not listed on the initial petition may require a separate filing and cause significant delays.
File DS-160 for each child
After the parent's case reaches Embassy Bangkok, each child completes a separate nonimmigrant visa application online. Do not combine multiple children on one DS-160 form.
Complete medical exams
Schedule individual medical examinations with a panel physician in Bangkok for each derivative applicant. Each child receives separate sealed medical results for embassy submission.
Gather birth certificates
Thai birth certificates must prove the parent-child relationship to the K-1 or K-3 beneficiary. Certified English translations are required for all Thai-language civil documents.
Attend consular interview
Children typically interview with the parent at US Embassy Bangkok. Present passports, birth certificates, custody documents, and non-traveling parent consent where applicable.
Enter US on K-2 or K-4
After visa approval, children enter the United States on derivative status tied to the parent. K-2 children typically adjust status with the K-1 parent after marriage within 90 days of US entry.
Document and evidence requirements
Download the live checklist on the official government website. Certified English translations are required for Thai-language documents.
| Requirement | Detail |
|---|---|
| Birth certificate | Thai original showing parent-child relationship |
| DS-160 | Separate online application for each child |
| Passport | Valid travel document for each derivative |
| Medical exam | Individual sealed results per child |
| Photos | Passport photos per embassy specifications |
| Custody documents | If applicable: divorce or custody orders |
| Passport consent | From non-traveling parent if required |
Route comparison overview
Compare this route with general alternatives. Always confirm the correct visa category for your purpose before lodging.
| Topic | This route | Alternative |
|---|---|---|
| K-2 | Child of K-1 fiancé beneficiary | Enters US with parent on K-1 |
| K-4 | Child of K-3 spouse beneficiary | Rare, most use IR-2 or CR-2 instead |
| Age-out risk | Must remain under 21 at visa issuance | CSPA may protect some cases |
| TVC support | Document prep for family group | Each child needs complete file |
What you cannot do
These restrictions apply during K-2 and K-4 processing and after US entry.
- Submit false relationship or custody information
- Travel without required non-traveling parent consent
- Miss embassy deadlines for individual child applications
After approval
Once K-2 or K-4 visas are approved, complete these steps before and after family travel.
- Review each child's visa foil before family travel
- Carry original birth certificates and custody documents
- K-2 children follow parent's 90-day marriage and I-485 timeline
- Do not let children work before adjustment of status approval
Additional guidance
K-2 for K-1 families
Unmarried children under 21 of the K-1 beneficiary may receive K-2 visas to enter the US with their parent. After the parent marries the US citizen sponsor within 90 days, K-2 children typically adjust status alongside the K-1 parent.
Documentation per child
Each child needs a separate DS-160, medical exam, passport, and birth certificate with translation. One combined file for multiple children is insufficient: embassy processing is individual per derivative applicant.
Custody and consent rules
If only one parent is traveling or the parents are divorced, Embassy Bangkok may require notarized consent from the non-traveling parent or a custody order from Thai courts.
Age-out and CSPA protection
Children must be unmarried and under 21 at visa issuance. The Child Status Protection Act may protect some who turn 21 during processing. Consult a US immigration attorney if a child is near the age limit.
K-4 reality check
K-4 visas for children of K-3 beneficiaries are rarely used in practice. Most married couples with children pursue CR-1 or IR-1 spouse visas with CR-2 or IR-2 derivative immigrant visas instead.
Bangkok family coordination
Thai Visa Centre helps K-1 and K-3 families prepare birth certificates, custody documents, certified translations, and coordinated family document packs before Embassy Bangkok interviews.
Common mistakes
These errors show up repeatedly in our Bangkok consultations for this visa category.
- Not listing all eligible children on the initial petition
- Single DS-160 for multiple children
- Missing custody or consent documents for split families
- Child turning 21 during processing without CSPA analysis
Frequently asked questions
Quick answers to follow-up questions about K-2 and K-4 derivative visas from Thailand.
Q:Can my child come on the K-1 with me?
A:Yes. Eligible unmarried children under 21 of the K-1 beneficiary may apply as K-2 derivatives on the same I-129F petition. Each child needs a separate DS-160 and medical exam.
Q:Does each child need a separate interview?
A:Procedures vary by embassy. At US Embassy Bangkok, children typically interview together with the K-1 parent. Each child still needs individual DS-160, medical exam, and passport.
Q:What is a K-4 visa?
A:K-4 is for unmarried children under 21 of a K-3 spouse beneficiary. K-3 visas are rarely used today, most families use CR-1 or IR-1 immigrant visas with CR-2 or IR-2 for children instead.
Q:Can K-2 children adjust status after US entry?
A:Yes. K-2 children typically file Form I-485 to adjust status with the K-1 parent after the parent marries the US citizen sponsor within 90 days of US entry.
Q:Can I apply from Bangkok?
A:Yes. K-2 and K-4 derivative processing for Thai residents takes place at US Embassy Bangkok after the parent's petition is approved and NVC or embassy instructions are issued.
Q:Does TVC submit my application?
A:Thai Visa Centre prepares birth certificates, custody documents, certified translations, and family document packs. You lodge DS-160 and attend embassy interviews through official State Department channels.
Q:Does TVC help with K-2 documents?
A:We prepare birth certificates, certified translations, custody consent letters, and coordinated family document packs from Bangkok for K-1 families with children.
Q:When was this guide last reviewed?
A:June 2026. K-2 and K-4 rules and embassy procedures change periodically. Verify current requirements on USCIS and travel.state.gov within two weeks of filing.
Official references
Official sources verified June 2026. Confirm current fees and checklists on official government sites before applying.