Cestovní pojištění lze sjednat po telefonu.

Cestovní pojištění means travel insurance.

• cestovní = travel, related to travel
• pojištění = insurance

Grammatically:

• pojištění is a neuter singular noun
• cestovní is the adjective describing it, so it has to match it in gender, number, and case

In this sentence, pojištění is the object of sjednat (to arrange / to take out), so it is in the accusative.
However, for many neuter singular nouns, the nominative and accusative look the same, so pojištění does not change form.

So although the form looks unchanged, it is functioning as the object: travel insurance.

Lze means something like:

• it is possible
• one can
• can be

So Cestovní pojištění lze sjednat... literally means something like:

• Travel insurance can be arranged...
• It is possible to arrange travel insurance...

A very important point: lze is impersonal.
That means it does not have a normal subject like já, on, oni, etc.

You do not use it like a regular verb such as:

• já lze ❌
• oni lze ❌

Instead, it stays fixed as lze and is followed by an infinitive:

• lze sjednat
• lze koupit
• lze použít

This structure is common in formal or written Czech.

Because lze is used to express possibility, and the action itself is given by the infinitive.

Here:

• lze = it is possible / can
• sjednat = to arrange / to take out

So:

• lze sjednat = can be arranged / it is possible to arrange

This is a very common pattern:

• Lze použít kartu. = A card can be used.
• Lze to udělat online. = It can be done online.

So in your sentence, sjednat tells you what action is possible.

In this context, sjednat means to arrange, to conclude, or very naturally in English, to take out.

With insurance, Czech often uses sjednat for entering into an insurance contract.

So:

• sjednat pojištění = to take out insurance
• sjednat smlouvu = to conclude / arrange a contract

This verb is more formal and specific than a general verb like koupit (to buy).
With insurance, sjednat is the normal idiomatic choice.

Czech often prefers structures like lze + infinitive to express general possibility in a formal, neutral way.

So:

• Cestovní pojištění lze sjednat po telefonu.

means roughly:

• Travel insurance can be arranged by phone.

A more directly passive-looking version is also possible in some contexts, but lze + infinitive is very natural in notices, instructions, advertisements, and formal writing.

It feels a bit like English:

• Tickets can be bought online.
• Applications can be submitted electronically.

So this sentence has a neutral, informational tone.

Po telefonu means by phone or over the phone.

The preposition po here is used in the sense of communication via a means or channel. With this meaning, it takes the locative case.

That is why you get:

• telefon → telefonu in the locative singular

So:

• po telefonu = by phone / over the phone

This is a set expression worth remembering.

Compare:

• mluvit po telefonu = to talk on the phone
• objednat po telefonu = to order by phone

They are very close in meaning.

• po telefonu = by phone / over the phone
• telefonicky = by phone / by telephone

In many situations, both are possible:

• Cestovní pojištění lze sjednat po telefonu.
• Cestovní pojištění lze sjednat telefonicky.

The difference is mostly stylistic:

• po telefonu sounds a bit more concrete and everyday
• telefonicky can sound slightly more formal or administrative

Both are correct and natural.

Because Czech often leaves the agent unspecified when the meaning is general.

This sentence is not talking about a specific person. It means something like:

• You can arrange travel insurance by phone
• One can arrange travel insurance by phone
• Travel insurance can be arranged by phone

English often needs to choose one of these styles, but Czech can stay more neutral.

That neutrality comes from the structure:

• lze + infinitive

So the sentence is about what is generally possible, not about who does it.

Yes, Cestovní pojištění si lze sjednat po telefonu is also possible.

Here, si is the dative reflexive pronoun and suggests doing something for oneself:

• sjednat si pojištění = to take out insurance for oneself

So:

• Cestovní pojištění lze sjednat po telefonu.
  neutral, general
• Cestovní pojištění si lze sjednat po telefonu.
  emphasizes that a person can take it out for themselves

In advertising or customer-facing language, si is very common because it sounds personal and natural.

No, Czech word order is fairly flexible, but different orders can sound more or less natural depending on emphasis.

The given sentence:

• Cestovní pojištění lze sjednat po telefonu.

is a very normal neutral order.

Other orders are possible, for example:

• Po telefonu lze sjednat cestovní pojištění.
• Lze sjednat cestovní pojištění po telefonu.

These all mean basically the same thing, but the emphasis shifts:

• starting with po telefonu highlights the method
• starting with lze sjednat sounds more formal or notice-like
• starting with cestovní pojištění makes the topic clear immediately

So the original version is natural and well-balanced.

Yes, it is slightly formal or informational in tone.

That comes mainly from:

• lze
• sjednat

This kind of wording is very common in:

• websites
• brochures
• insurance information
• official notices
• customer service texts

In more everyday spoken Czech, people might say something like:

• Cestovní pojištění se dá sjednat po telefonu.

That means the same thing, but sounds a bit more conversational.

So:

• lze sjednat = more formal/written
• dá se sjednat = more everyday/spoken

A native speaker would understand it as a neutral statement of possibility:

• Travel insurance can be taken out by phone.
• You can arrange travel insurance over the phone.

The tone is practical and informational, like something you might read on an insurance website.

A useful way to remember the structure is:

• [thing] + lze + infinitive + po telefonu
• [thing] can be arranged by phone

So this sentence is a good model for similar formal Czech phrases.