Biarkan khidmat pelanggan semak bukti pembelian.

Yes. It is an imperative sentence.

Malay often leaves out the subject you in commands, so the understood meaning is:

• (You) let customer service check the proof of purchase.

That omission is completely normal in Malay.

Here, biarkan means let or allow.

The pattern is:

• biarkan + person/party + verb

So:

• Biarkan khidmat pelanggan semak...
  = Let customer service check...

The word comes from biar, and biarkan is a very common form in instructions and requests.

After words like biarkan, Malay often uses the next verb in its base form, so semak is natural here.

So this is normal:

• Biarkan khidmat pelanggan semak bukti pembelian.

A fuller version is also possible:

• Biarkan khidmat pelanggan menyemak bukti pembelian.

That sounds a bit more formal or complete, but the shorter version is very common and natural.

Malay does not need a separate word like English to in this structure.

English says:

• Let customer service check...

Malay says:

• Biarkan khidmat pelanggan semak...

So the sentence goes straight from khidmat pelanggan to semak without adding anything equivalent to to.

Khidmat pelanggan is the standard Malay term for customer service.

It breaks down as:

• khidmat = service
• pelanggan = customer

As a phrase, it usually refers to the customer service department, desk, or staff as a group. Malay does not force you to mark this as singular or plural the way English often does.

This is a very common Malay noun phrase pattern:

• bukti = proof
• pembelian = purchase / buying

Together:

• bukti pembelian = proof of purchase

Malay often puts nouns together directly like this, without a word like of.

Also, pembelian is derived from beli (to buy), so it means purchase or the act of buying.

Malay usually does not use articles like a/an/the.

So khidmat pelanggan can mean:

• customer service
• the customer service department

And bukti pembelian can mean:

• proof of purchase
• the proof of purchase
• your proof of purchase

The exact meaning usually comes from context. If the speaker wants to be explicit, they can add a possessive:

• bukti pembelian anda = your proof of purchase

Yes. Biarkan can also mean leave, leave alone, or leave as it is, depending on the sentence.

For example:

• Biarkan dia pergi. = Let him go.
• Biarkan saya. = Leave me alone / let me be.
• Biarkan pintu itu terbuka. = Leave that door open.

In your sentence, because biarkan is followed by khidmat pelanggan + semak, the meaning is clearly let/allow.

Yes. Khidmat pelanggan sounds standard and fairly formal-neutral.

You may also hear:

• servis pelanggan

That version is also common, especially in everyday business usage and speech influenced by English. But khidmat pelanggan is a very good standard-Malay choice.

Yes. For example:

• Biarkan khidmat pelanggan menyemak bukti pembelian anda.

This version feels fuller because it adds:

• menyemak instead of semak
• anda to make your proof of purchase explicit

The original sentence is still natural; it is just more compact.