Не надсилайте ПІН-код шахраєві.

Надсилайте is the imperative form of the verb надсилати, so it means send! or, with не, don’t send.

More specifically, it is:

• 2nd person plural imperative
• also used as a polite/formal singular command

So Не надсилайте = Don’t send.

It can be either:

• to several people: Don’t send...
• to one person politely/formally: Don’t send...

That is very common in Ukrainian. The ending -йте does both jobs.

If you were speaking to one person informally, you would usually say:

Не надсилай ПІН-код шахраєві.

Because in Ukrainian, не is usually written separately with finite verb forms.

So:

• надсилайте = send
• не надсилайте = do not send

This is the normal spelling pattern for negating a verb in a sentence like this.

Because шахраєві is in the dative case.

The verb надсилати usually works like send something to someone, and the recipient goes in the dative:

• ПІН-код = the thing being sent
• шахраєві = to the scammer

The dictionary form is шахрай. In this sentence, it changes to шахраєві because of its role in the sentence.

Yes. Both are possible dative singular forms of шахрай:

• шахраєві
• шахраю

Both mean to the scammer.

Шахраєві may sound a little fuller or more formal in some contexts, but both are standard and natural.

Because it is the direct object, so it is in the accusative case, and for many inanimate masculine singular nouns in Ukrainian, the accusative looks the same as the nominative.

So:

• nominative: ПІН-код
• accusative: ПІН-код

That is why the form does not visibly change.

Because ПІН is an abbreviation, and код is a regular noun.

In Ukrainian, combinations like abbreviation + noun are often written with a hyphen, so:

• ПІН = the abbreviation
• код = code
• together: ПІН-код

The capital letters show that ПІН is an acronym/initialism.

This is about aspect.

• надсилати is imperfective
• надіслати is perfective

In warnings, instructions, and general prohibitions, Ukrainian very often uses the imperfective in negative commands:

• Не надсилайте... = Don’t send... / Do not send...

This sounds natural for a general rule or safety warning.

A perfective negative imperative can sound more like a warning about one specific completed action, and it is less natural in a broad instruction like this. So Не надсилайте ПІН-код шахраєві is the most natural choice here.

No. The singular here can be generic.

So шахраєві means to a scammer in the general sense, not necessarily one specific scammer. This is very normal in warnings and advice.

It works like English Don’t send your PIN to a scammer — not just one particular scammer, but any scammer.