Gecikme zammı bakiyeye eklendi.

Because gecikme zammı is a common Turkish noun-compound pattern.

• gecikme = delay, lateness
• zam = increase, surcharge, extra charge

In this kind of compound, the second noun usually takes the compound suffix -(s)I:

• gecikme zammı = late fee / delay surcharge

So the structure is not random; it is a normal way to build expressions like X fee, X door, X color, etc. in Turkish.

That happens because zam takes a vowel-initial suffix here, and some Turkish words double their final consonant when that happens.

So:

• base form: zam
• with the suffix: zam + ı
• result: zammı

This is something you just have to get used to with certain words. It is not a separate meaning change; it is just how the word behaves when a suffix is added.

Bakiyeye is bakiye + the dative ending.

• bakiye = balance
• -e / -a = to, onto, sometimes into

So:

• bakiye = balance
• bakiyeye = to the balance / onto the balance

The extra y is a buffer consonant. Turkish often inserts y between two vowels so the word is easier to pronounce:

• bakiye + e → bakiyeye

Because with eklenmek in this meaning, Turkish marks the thing receiving the addition with the dative case.

So:

• bakiyeye eklendi = was added to the balance

This is very natural in Turkish. English uses to, while Turkish often uses the dative ending -e / -a instead.

Eklendi can be broken down like this:

• ekle- = add
• -n- = passive marker here
• -di = past tense

So eklendi means was added.

Compare:

• ekledi = he/she/it added
• eklendi = it was added

That is why the sentence sounds passive in English.

Turkish often uses the passive when the person or institution doing the action is unimportant, unknown, or simply not mentioned.

So:

• Gecikme zammı bakiyeye eklendi. = The late fee was added to the balance.

The focus is on the result, not on who added it.

If you wanted an active sentence, it could be something like:

• Banka gecikme zammını bakiyeye ekledi. = The bank added the late fee to the balance.

The grammatical subject is gecikme zammı.

Even though English learners sometimes associate the subject with the doer of the action, that is not always true. In a passive sentence, the subject is the thing affected by the action.

So here:

• gecikme zammı = subject
• bakiyeye = dative complement
• eklendi = verb

In other words, the late fee is the thing that was added.

Literally, it is something like:

• Gecikme zammı = late fee
• bakiyeye = to the balance
• eklendi = was added

So a very literal rendering would be:

• Late fee to-the-balance was-added.

This is normal Turkish word order: important sentence elements come before the verb, and the verb usually comes last.

Yes. Turkish word order is more flexible than English because the suffixes already show the grammatical relationships.

For example, these are all possible depending on emphasis:

• Gecikme zammı bakiyeye eklendi.
• Bakiyeye gecikme zammı eklendi.

Both mean essentially the same thing, but the emphasis shifts a little.

• Starting with Gecikme zammı highlights what was added.
• Starting with Bakiyeye highlights where it was added.

Because Turkish does not have articles like English a and the.

Whether you translate it as a late fee or the late fee, a balance or the balance, depends on context.

So Gecikme zammı bakiyeye eklendi can naturally become:

• The late fee was added to the balance
• or, in another context, A late fee was added to the balance

English must choose an article, but Turkish does not.

Yes. It sounds like the kind of sentence you would see in:

• a bank statement
• a billing notice
• an account summary
• a debt or payment message

Words like bakiye and gecikme zammı are common in financial and administrative Turkish, so the whole sentence has a formal, account-related tone.