Where Do I Start a Subclass 300 Application in ImmiAccount in 2026?

Plain-language guide · general information, not immigration advice

In ImmiAccount, a Prospective Marriage visa (Subclass 300) application starts here: log in, choose New application, then Family, then Stage 1 – Partner or Prospective Marriage Visa. That is the path published on the Australian Department of Home Affairs' official Prospective Marriage visa (Subclass 300) page, as of the July 2026 version of that page. Two conditions sit behind those clicks: the application must be lodged online, and you must be outside Australia when you lodge it.

What exactly do I click, and in what order?

The official page sets out the online sequence as nine moves:

Log in to ImmiAccount — if you have no login, you will be asked to create an account.
Select New application.
Select Family.
Select Stage 1 – Partner or Prospective Marriage Visa.
Complete your application.
Pay the visa application charge.
Submit your application.
Give your transaction reference number (TRN) to your sponsor, who needs it to apply for sponsorship.
Attach supporting documents to the completed application.

Payment is not a formality: the page states that the application cannot be processed if the correct visa application charge is not paid. Attachment is the ninth step, not a prerequisite — you lodge the form first, then load documents into it.

Why is Subclass 300 filed under "Family" and "Stage 1"?

Because the partner programme is organised in stages, and Subclass 300 belongs to the first one. It is the visa for people who intend to marry their prospective spouse before the visa period ends; the official overview lists the eligibility framing as being 18 or older, having a sponsor who is an Australian citizen, permanent resident or eligible New Zealand citizen, having met your prospective spouse face to face as adults since turning 18 and knowing each other personally at the time you apply, and being outside Australia when you apply along with any family applying with you.

The menu label covers that first stage, so the trap for people hunting through the visa list is to look for "Prospective Marriage" as a top-level category. It is not one — you reach it through Family.

What should be ready before I click "New application"?

Nothing in the online form replaces the evidence itself, and the official page is explicit that applications with all required information reduce processing delays. Before starting:

Identity documents: a birth certificate showing the names of both parents, or one of the listed alternatives (family book identification pages, government-issued identification document, court-issued identity document, or family census register). Also the pages of your current passport showing photo, personal details and issue and expiry dates; a national identity card if you have one; and proof of change of name where applicable.
Relationship evidence: your relationship with your prospective spouse, any former relationships, and any dependants.
Translations: everything into English, with both original and translation provided. Translators in Australia must be accredited by NAATI; translators outside Australia need not be accredited but must include their full name, address and telephone number, and their qualifications and experience in that language, in English.
Scans: colour, legible, one file per multi-page document. Certification is not required.
Form 80 (Personal particulars for assessment including character assessment), completed and attached.
Police certificates from every country where you spent a total of 12 months or more during the last 10 years since you turned 16, plus military service records or discharge papers if you served. For immigration purposes police certificates are valid for 12 months from issue; for an Australian certificate, only complete disclosure National Police Certificates from the Australian Federal Police are accepted, and if more than 15 months has passed since that certificate was issued, new checks will be required.
Your own contact details: the partner visa application form asks for your own phone number and email address, and the page stresses providing your own, because the department may need to contact you directly even if you have nominated your sponsor's email or appointed someone to receive correspondence.

Health examinations are also required — a visa cannot be granted without a valid health assessment, results are valid for 12 months from when you completed the examinations, and any health undertaking you are asked to sign is valid for 6 months. The official page suggests checking global visa processing times before deciding when to do them.

Where do the documents go, and how many can I attach?

They go into the application you have already submitted, in ImmiAccount. The limits are mechanical, so it helps to know them before you start uploading:

Rule	What the official page says
Attachment cap	Up to 100 documents for each person on the application
Increasing the cap	The attachment limit cannot be increased
If one applicant hits the cap	You can attach more documents to other clients on the application
Duplicates	Clearly label documents and attach each one only once, even if it proves more than one thing
Missing documents	Attach them in ImmiAccount as soon as you can; the department may also ask for more. The official page also names the Partner Processing Enquiry Form for cases where documents cannot be uploaded to ImmiAccount.
Keeping records	Keep a copy of your completed application

What changes the moment I submit?

Three things. First, a TRN exists — hand it (or the application ID) to your sponsor, because sponsorship is applied for separately and the page says your sponsor should apply to sponsor you as soon as possible after you apply. You and anyone applying with you must have a sponsor both at lodgement and while on the visa.

Second, sponsorship and assessment run in parallel with your document uploads. The department will let you know it has received the application. If your application is within standard processing times, the page's instruction is not to request progress updates; you can see in ImmiAccount whether more information has been asked for.

Third, your own circumstances become reportable. If you marry before the decision, you are no longer eligible for Subclass 300: you must update ImmiAccount via the 'Update details' tab and 'Change in situation', attach evidence the marriage is valid, a request to be considered for a Partner (Provisional) visa (subclass 309) and Partner (Migrant) visa (subclass 100), and a statement requesting withdrawal of the Subclass 300 application, and, after updating ImmiAccount, notification must be made through the Partner Processing Enquiry Form named on the official page. If you do not withdraw, the application will be refused, since you no longer meet the eligibility requirements.

What most often goes wrong at this stage?

Lodging from inside Australia. Both you and any family applying with you must be outside Australia when you apply.
Using the sponsor's contact details as your own. The form asks for your phone and email for a reason.
Waiting for a "complete" file before starting. Documents are step 9, not step 1; delaying the form only delays the TRN your sponsor needs.
Choosing the wrong branch of the menu. Subclass 300 is reached through Family → Stage 1, not through a standalone "Prospective Marriage" option.
Booking travel. Do not arrange to travel to Australia until the department tells you in writing that the Subclass 300 visa has been granted.

The lodgement condition on the official page is that the applicant is outside Australia at the time of applying, so complete the form and submit it only once outside Australia.

Everything above describes published procedure and is general information, not advice tailored to any one person's circumstances; where your situation involves sponsorship history, prior refusals or character issues, rely on the department's current page and on a professional who is lawfully able to give immigration assistance.

Frequently Asked Questions

Do I need an ImmiAccount before I can start a Subclass 300 application?

Yes. The official application path begins with logging in to ImmiAccount, and if you do not have a login you will be asked to create a new account. The account is also where you later attach documents, check whether more information has been requested, and update your details.

Which menu path leads to Subclass 300?

New application → Family → Stage 1 – Partner or Prospective Marriage Visa. The subclass sits under the Family category because the partner programme is structured in stages, and Subclass 300 belongs to the first stage.

Can I start the application while I am in Australia?

You can prepare, but you must apply online and while outside Australia, as must any family members applying with you. The department may need to be satisfied of this at lodgement, so the form should only be submitted once you are outside Australia.

How many documents can I attach, and can I add more after submitting?

You can attach up to 100 documents for each person on the application, and the limit cannot be increased. If one applicant reaches the cap, further documents can be attached to other clients on the same application, and anything you did not attach at lodgement should be added in ImmiAccount as soon as possible.

What is the TRN and who needs it?

The transaction reference number is generated when you submit, and it identifies your application. Your sponsor needs it to apply to sponsor you, and the official guidance is that the sponsor should apply as soon as possible after you lodge.

What happens if I marry before the department decides?

You stop being eligible for Subclass 300. You are asked to update ImmiAccount through 'Update details' → 'Change in situation', attach proof the marriage is valid, request consideration for subclasses 309 and 100, ask to withdraw the Subclass 300 application, and, after updating ImmiAccount, notification must be made through the Partner Processing Enquiry Form named on the official page; without withdrawal, it will be refused.

Is the application fee refunded if the visa is refused?

No. The official page states that the application fee will not be refunded if the application is refused, and the decision letter will explain why and whether you have a right to review.

Can I add a dependent child after lodging?

Yes, before a decision is made, provided the child is outside Australia. This is done by completing and attaching Form 1436 (Adding an additional applicant after lodgement) in ImmiAccount; the official page also names the Partner Processing Enquiry Form as the notification channel to be used once the form is attached, and the child can be granted the visa if they are a member of the family unit and meet the other criteria.