Statement of intent
Although you are currently employed, you are on a temporary contract. In that case, you’ll need a letter of intent from your employer. This is not the same thing as an employer’s statement (Dutch PDF), but it does constitute part of it.
In a letter of intent, your employer will state whether they intend to employ you permanently after your current contract expires, on the condition that your performance remains at the same level, and the business conditions remain the same. It is generally not a problem to obtain a letter of intent from your employer. After all, it is not a hard and fast guarantee that you will actually be given a permanent contract in due course.
Based on the employer’s statement, plus the letter of intent, the lender can determine whether you will be able to meet your mortgage repayments in the future. These documents together effectively serve as a permanent contract.
Are you still on a trial period?
To the lender, this means you do not have a valid income. In this case, you can only apply for a mortgage if your income is not required (e.g. because your partner has sufficient income) or if your trial period is about to end.
In the latter case, the contract that starts after your probationary period will be considered. Is it a permanent contract, or a temporary contract with a statement of intent? Subsequently, the income stated on the contract will be taken into account.
Have you not been offered a permanent or temporary contract after your trial period? If so, your maximum mortgage will be calculated based on your income over the past 3 years. The way your income is determined, in this case, is similar to that of a person who is self-employed.