yatin ha kouza kara hikiotosi ni sita node, maituki ginkou ni ikanakute mo ii desu.

は marks 家賃 as the topic: as for the rent...

So the sentence is not simply identifying rent as the subject; it is talking about rent as the thing under discussion. This can also imply a mild contrast, like as for the rent, I set it up this way.

If you used が, the nuance would be different. は is the most natural choice here for introducing what the speaker is talking about.

口座 means account, and in this sentence it almost certainly means a bank account.

So 口座から means from my account or out of my account.

Japanese often leaves out words like bank when the context already makes it clear.

から marks the starting point or source.

Here, the money is being withdrawn from the account, so 口座から is natural.

• 口座から引き落とし = withdrawal from an account
• If you changed the particle, the meaning would change

So から is doing the same job as from in English.

This uses the pattern noun + にする, which often means:

• to make something into ...
• to choose ...
• to set something as ...

Here:

• 引き落とし = automatic withdrawal / direct debit
• 引き落としにする = to set it up as automatic withdrawal, to choose direct debit as the payment method

So 引き落としにした means the speaker made it direct debit or set it up for automatic withdrawal.

Here, 引き落とし is functioning as a noun.

It comes from the verb 引き落とす, meaning to deduct or to withdraw from an account, but in this sentence it behaves like a noun meaning something like:

• automatic withdrawal
• direct debit
• bank deduction

That is why it can be used with にする.

ので means because / since, but it usually sounds a bit softer, more explanatory, and often a little more polite than から.

Compare:

• したので = since I did that..., because I did that...
• したから = because I did that...

Both are possible, but ので often sounds more like calmly giving a reason. In this sentence, that fits well: Since I set the rent to direct debit, I don’t have to go to the bank every month.

In ordinary polite Japanese, the part before ので is often in the plain form, even if the whole sentence is polite overall.

So this is very normal:

• 引き落としにしたので、...いいです。

The sentence is still polite because it ends with です.

You can say しましたので, but that sounds more formal or businesslike. In everyday speech, したので is very natural.

This is a very important pattern:

• verb-なくてもいい = do not have to verb
• literally: it’s okay even if you don’t verb

So:

• 行かなくてもいいです = it’s okay not to go
• natural English: I don’t have to go

This does not mean must not go.

For must not go, Japanese would use something like:

• 行ってはいけません
• 行かないでください depending on the situation

Here, も is part of the fixed grammar pattern -ても / -なくても, which means even if.

So:

• 行かなくても = even if I don’t go
• 行かなくてもいい = it’s okay even if I don’t go

You should learn なくてもいい as one chunk. In this pattern, も is not the usual also meaning.

Yes, へ is possible, but に is very common and natural with 行く.

• 銀行に行く = go to the bank
• 銀行へ行く = go toward/to the bank

In many cases, the difference is small. に often feels like a straightforward destination marker, while へ can feel a bit more directional. In this sentence, 銀行に行く is the most natural everyday phrasing.

Japanese often leaves out subjects when they are clear from context.

In this sentence, the unstated subject is probably the speaker:

• I set the rent to be paid by direct debit
• so I don’t have to go to the bank every month

Japanese does this all the time. If the subject is obvious, it is usually omitted rather than repeated.

毎月 means every month, and it modifies 銀行に行く.

So the meaning is:

• I don’t have to go to the bank every month

Japanese time expressions often appear before the action they relate to, so 毎月 naturally comes before 銀行に行かなくてもいいです.

You could think of the structure like this:

• Since I set the rent to direct debit,
• every month, going to the bank is unnecessary.