Question suggested by my friend Gianina Froicu
It all depends on the position you are being interviewed for and the location of the interview.
1. For a manager position - always use business dress code. You will meet other managers for sure, especially if the interview is at the company headquarters. There are exceptions concerning the location of the interview of course. One of my colleagues - Transition manager- was interviewing a candidate from a different city and they decided to meet at the airport in a cafe place since our manager was spending 5 hours between flights and the candidate's residence was in that location. In this case you may still dress business - maybe just lose the tie because of the more casual place to meet, but still be business to make sure you make a good impression.
2. For a senior specialist - if you expect to be working on a position which will require business dress code daily (like Key accounts manager in sales), don't hesitate and use business dress code. If you expect to be working on a position and in a company where dress code is not specified (like programmer, web designer, economist), use business casual. What's business casual? Your regular clothes, always neat and clean, always decent, but without jeans and sports wear.
3. For a junior specialist - if you expect to be working on a position which will require business dress code daily (like Front office clerk in a bank), again don't hesitate and use business dress code. Else, please see above. Business casual is fine for the interview, even if later you will use your sports shoes on the job and so on. Try for the interview to be a little better dressed than you would be on a regular day on the job.
4. For a skilled worker position - most of the times the interview will include practical tasks. Business dress code is not very common. Just use your regular clothes that you would use on a normal day. Just remember the neat, clean and decent rule.
Rules 1-4, except the special case I mentioned in 1., apply mainly if you go to the headquarters of the company. If you are invited in a different location - which is not very common but may happen - like in a restaurant or bar (the company may not have an office where you live - i.e. you will be a sales agent working from home in your city), try to dress neat, clean and decent, but more on the casual side than on the business side. Strict business dress in a bar looks a bit ridiculous. Your intuition can also help or simply asking the person scheduling the interview can save you a lot of trouble.
What to always remember - no matter what you decide to wear, neat, clean and decent are always the answer. Make sure you have clean clothes, not too colourful, decent, no wrinles, no holes, no torn materials, no stains and so on. I remember a guy who came to me for an interview at 11 am - he had just woken up, he hadn't washed his face, his T-shirt looked like he had slept in it and his hair was all untidy and messed up. Of course he didn't convince me. He might have been smart, but I didn't see it no matter what. Always try to make a first good impression - be always neat, tidy, decent and clean and no matter if you don't select the correct dress code all the time, you have a chance.