Your require a visa to vist some counties, but not others
A visa is not required for every country
Different countries have different visa criteria and quite often you do not need a visa to enter
The world visa system may seem complicated to someone who has only recently started to think about travelling abroad. Some countires have no visa requirements for entry, while other countries seem very strict to almost every other countries' visitors Fees for visas are common and sometimes these may be excessive. The process for applying for a visa may be long and fraiught with difficulties. The main point is that there is amazing variation of visa procedures amongstthe world's countries.
Depending on the country you plan to visit will depend on if you need a visa or not.
If you need a visa or not depends on what countries you plan to visit.
"Depending on the country you plan to visit will depend on if you need a visa or not." This explains that different countries have different visa requirements so if you need to get a visa will depend on which countries you want to travel to.
"If you need a visa or not depends on what countries you plan to visit." This is another way of explaining that some countries you will need a visa to visit but for others you won't so you have to choose the country to find out if you need a visa or not.
"Depending on the country you plan to visit will depend on if you need a visa or not."
（訪れる予定の国によってビザの要不要は決まります）
これはそれぞれの国によってビザの必要条件はそれぞれ異なるので、
どの国に旅行したいかによってビザの要不要は決まります、
と言う事を説明しています。
"If you need a visa or not depends on what countries you plan to visit."
（どの国に旅行したいかによってビザの要不要は決まります）
これはもう一つの表現でいくつかの国はビザが必要だけど、
ビザの必要のない国もあるので、国を選んでからビザが必要か不要なのかは分かる、
と言う事を説明しています。
Whether you need a visa or not depends on the country you're visiting
Some countries don't require a visa to visit
A visa is a travel document that lets you into another country to enter and stay for a certain amount of time not all countries you visit require a visa to enter but some do you can explain this by 'some countries don't require a visa to visit'
A visa'（ビザ）は海外に一定期間滞在するときに必要となる文書のことです。
入国の際にビザが必要な国と必要でない国がありますね。これについて説明するなら次のように言えます。
'some countries don't require a visa to visit'
（ビザなしで入国できる国もあります）
Whether you need a visa or not depends on the country you are visiting.
You do not need a visa for all countries.
A visa is not needed for every country.
You can visit some countries for 30 days without a visa.
You don't need a visa for certain countries.
You need a visa to visit some countries, but not all.
Whether you need a visa or not depends on the country you are visiting.
You do not need a visa for all countries.
You can visit some countries for 30 days without a visa.（国によって30日以内の滞在であればビザが要らない所があります）
You don't need a visa for certain countries.（国によってビザが要らない所もあります）
You need a visa to visit some countries, but not all.（国によってビザが必要な所と必要でない所があります）
Whether you need a visa or not depends on the country you are visiting.（ビザが要るかどうかは訪れる国によって違います）
You do not need a visa for all countries.（国によってビザが要らない所もあります）
You don't need a visa when traveling to some countries.
Some countries don't have visa requirements.
Countries like Senegal, Brazil, and Sri Lanka don't require a visa to travel there.
Usually, countries with certain agreements allow their citizens to travel there without visas.
You can use the sentences above to explain that you won't always need a visa to travel.
Requirements: something that is needed
Needing a Visa will depend on the country you enter
Depending on the country you visit may require you to have a Visa
"Needing a Visa will depend on the country you enter"
'Needing' is a term used when in 'need' of something, something that you must have.
'Visa' is a document issued by a country to allow entrance to their country.
"Depending on the country you visit may require you to have a Visa"
To 'require' something is something you will need for a particular purpose, in this case a Visa for a specific country.
"Needing a Visa will depend on the country you enter"（ビザが必要かどうかは訪れる国によります）
'Needing' は「～が必要である」という意味です。
'Visa' は入国許可証のことで、訪れる先の国によって発行されます。
"Depending on the country you visit may require you to have a Visa"（訪れる国によってビザが必要になる場合があります）
'require' は「〔あることに〕～が必要である」という意味です。この場合は、特定の国のビザが必要ということです。
The question of whether or not you need a visa depends upon the country you visit.
Visa requirements vary from country to country.
Visa requirements vary by country
The question of whether or not you need a visa depends upon the country you visit. For example, Japan previously required Thai people to obtain a visa from the Japanese consulate in Bangkok in order to visit Japan. However, they recently withdrew this requirement and Thais no longer need a visa to visit Japan, all they need to do is to present their passport at the immigration counter. European countries and the US, however, still require Thai people to obtain a visa in order to enter their countries.
イギリス 
南アフリカ 
アイルランド 
アメリカ合衆国 
