Question: I've been working at a newly established firm for over a month and I haven't signed a contract yet.

HR kept telling me that they needed time to prepare contracts for everyone, but I've asked almost everyone else in my department and they've all said that they signed their contracts 2-3 weeks ago.

I asked the HR girl again and she said "Wow, you haven't signed your contract yet? Ok let me check and see what happened".

I agreed to a starting salary until signing the contract, and was told that after signing the contract the salary would be set depending on my position.

The firm has come together in a somewhat experimental way, allowing people to fall into their positions naturally.

Now that I've been with the firm for over a month, is it to my advantage or theirs?

Can I leverage the fact that I'm now established and comfortable in my position (i.e. they would need a few weeks to train a replacement to my level) and can I use this to negotiate a higher salary?

Or is it to their advantage?

Answer: 
> 
> Can I leverage the fact that I'm now established and comfortable in my
>  position (i.e. they would need a few weeks to train a replacement to
>  my level) and can I use this to negotiate a higher salary?
> 
> 
> 

You can always try. It doesn't seem like much in the way of leverage to me.

You already agreed to a pre-contract starting salary and agreed that your salary would be set depending on your position. 

You will be going back on your word if you use your "leverage". You get to decide if that the way you want to come across in your new position in a new company.

It's not something I would do, but you could certainly try.
Not having a written contract is usually bad for both sides, but almost always worse for the employee than for the employer.

The reason is that when there is a disagreement about how much salary they need to pay the employee, then the employer is in a much better position. They can withhold payment, but the employee can not undo their work. Also, the employee is usually more dependent on their monthly salary than the employer is on their work. So the employer can bide time until the employee runs out of money and must agree to a detrimental settlement to pay their rent.

So bottom line, you want a written contract as soon as possible. You usually should not even start working without one.