Op dit formulier moeten zowel je adres als je postcode staan, plus de naam van de afzender en de ontvanger.

Op dit formulier means on this form. In Dutch, you often use op with things like forms, lists, pages, and signs when you mean that information appears there in writing.

So:

• op dit formulier = on this form
• op de lijst = on the list
• op de pagina = on the page

Starting the sentence with this phrase puts the focus on the form itself. It is a very normal Dutch word order choice.

Because the subject is plural.

The subject is not just one thing. It is:

• zowel je adres als je postcode, plus
• de naam van de afzender en de ontvanger

That is more than one required item, so Dutch uses the plural form moeten.

Compare:

• Je adres moet op het formulier staan. = Your address must be on the form.
• Je adres en je postcode moeten op het formulier staan. = Your address and postcode must be on the form.

Zowel ... als ... means both ... and ....

In this sentence:

• zowel je adres als je postcode = both your address and your postcode

It is a set expression:

• zowel X als Y

Examples:

• Ik spreek zowel Nederlands als Engels. = I speak both Dutch and English.
• Zowel koffie als thee is verkrijgbaar. = Both coffee and tea are available.

It is a little more formal or structured than just X en Y.

In Dutch, staan is often used for text or information that is written, printed, or listed somewhere.

So:

• Je naam staat op het formulier. = Your name is on the form.
• literally, Dutch uses stands where English often uses is

This is very natural in Dutch when talking about information on paper, screens, signs, labels, and documents.

So moeten ... staan here means something like:

• must be written on it
• must appear on it

This is because of normal Dutch main-clause word order.

In a basic sentence, Dutch often has:

• Subject + verb + rest

But if another element comes first, the finite verb still stays in the second position. This is called V2 word order.

So compare:

• Zowel je adres als je postcode moeten op dit formulier staan.
• Op dit formulier moeten zowel je adres als je postcode staan.

In the second version, Op dit formulier comes first, so the verb moeten moves before the subject.

Je means your, so it already replaces an article:

• je adres = your address
• je postcode = your postcode

But in de naam van de afzender en de ontvanger, we are talking about the name of the sender and the recipient, not directly using a possessive like je.

So:

• de naam = the name
• van de afzender = of the sender
• van de ontvanger = of the recipient

This construction is very common in Dutch:

• de kleur van de auto = the color of the car
• de naam van het bedrijf = the name of the company

These are common postal or form-related words:

• de afzender = the sender
• de ontvanger = the recipient / receiver

So in contexts like mail or packages:

• afzender = the person sending something
• ontvanger = the person receiving it

They are very useful words for forms, shipping labels, and postal instructions.

Plus here means plus or and also.

So:

• ..., plus de naam van de afzender en de ontvanger. means
• ..., plus the name of the sender and the recipient.

It adds extra required information. In Dutch, plus is fairly common in everyday language, though sometimes en would also be possible depending on style.

It can sound slightly less formal or a bit more list-like than just en.

Because Dutch has a two-verb structure here:

• moeten = the finite verb
• staan = the infinitive

In a main clause, the finite verb usually comes in second position, and the infinitive often goes to the end.

So:

• Op dit formulier moeten ... staan.

This is a very common pattern:

• Ik moet morgen werken. = I have to work tomorrow.
• Je moet hier wachten. = You have to wait here.
• Op het formulier moet je naam staan. = Your name has to be on the form.

Yes. Je is informal your, while uw is formal your.

So a more formal version could be:

• Op dit formulier moeten zowel uw adres als uw postcode staan, plus de naam van de afzender en de ontvanger.

Use:

• je with friends, family, children, informal instructions
• uw in formal communication, customer service, official letters, or when addressing someone politely

Forms and instructions can use either, depending on the tone.

Yes, basically. Postcode is the Dutch word for postal code.

For an American English speaker, the closest everyday equivalent is zip code. For British English, it is postcode.

So:

• je postcode = your postal code / zip code

Yes. You could also say:

• Op dit formulier moeten je adres en je postcode staan ...

That still means the same thing in many contexts. But zowel ... als ... emphasizes that both items are required.

So the difference is roughly:

• je adres en je postcode = your address and postcode
• zowel je adres als je postcode = both your address and your postcode

The second version sounds a bit more explicit and careful, which fits instructions well.