Child MN1 (Section 3(1)) application and child’s status after visa expiry

I would appreciate your advice on the following:

My son (aged 17) applied for registration as a British citizen under Section 3(1) using Form MN1. He has lived in the UK continuously since 2015 (over 10 years). Both parents have recently been granted Indefinite Leave to Remain (ILR).
The MN1 application was submitted on January 2026, and biometrics were completed January 2026. His previous visa expired in February 2026.
The application is straightforward with no gaps in residence, no adverse immigration history, and good character. Referees have been provided.

I would like clarification on:

Whether my son is lawfully allowed to remain in the UK while the MN1 application is pending,

Whether it is advisable to submit an ILR application while the MN1 application is still under consideration, or to wait for the MN1 decision.

Any risks associated with his current status while awaiting a decision.

If I still have an option of applying ILR rather than waiting for MN1?

Thank you for your guidance.

He is an overstayer now and does not currently have lawful residence.

An MN1 application does NOT extend his previous visa category under Section 3C of the immigration rules as citizenship is not an immigration application. For registration, he must meet all the requirements :

https://www.gov.uk/government/publicati ... le-version

Children who have lived in the UK for more than 10 years
Children will come within this category if:

the child is in the UK lawfully

the parents are in the UK lawfully

both parents give their consent to registration (unless good reasons are provided)

there is no reason to refuse on character grounds.

Overstaying comes under the good character grounds, especially as an older child, where he must meet the good character requirement.

When exactly did you apply for him?

Why did you not apply in 2025 while the visa was still valid as soon as he reached 10 years in the UK?

I was waiting for our ILR to be processed for make this application strong, it was not known to me about the overstaying (I was under impression that an application with home office would cover stay).

I applied exactly one month and 10 days before his current visa expiry.

Should I apply for his ILR now to avoid this situation?

(I was under impression that an application with home office would cover stay).

This only applies to immigration applications, ie visa extensions or ILR. It does not apply to British Citizenship application as rhey are not immigration applications. A section 3(1) application is one at tbe home office discretion, no guarantee at all and can be refused (quite a few posts about refusals on the forum, mainly for child not have ILR) as non UK born children do not have any entitlement to register as British.

Don't know why you did not apply last year when the child reached 10 years residence and while the visa was still valid.

Even if you apply for ILR, he is still an overstayer since his visa expired.

When does he turn 18?

We got still 8 months for him to turn 18.

It was a genuine mistake on my end and understanding.

Can I submit ILR now for him explaining the situation.

Any recommendations would be helpful.

Just an update on our case for everyones benefit — the MN1 Section 3(1) application for our child has now been approved successfully.

But, I would recommend who is planning to apply for MN1 under section 3(1) child born outside UK to go for ILR first to be safe (If it is straight forward). If not pleas make sure your child has at least 8 months visa after biometrics.

MN1 does not cover Section 3c leave.

All the best to everyone who is planning to apply and thanks for the responses.