If you are that concerned about not being able to make the payment, you should probably stay with PAYG.

If you have been with PAYG for a long time than you were ahead of the curve. PAYG is catching on in the US, I see the currency marking shows you are not, but my point is PAYG is the way people are going and you have been there all along, why move to contract and get tied in to the commitment when you don't have to. Contracts are a hassle and often times Contract service is no better than PAYG, I fount that out the hard way. Paid for years to US Cellular then later decided to give PAYG a try and now I pay the same price I was paying with USC to VM and get unlimited service where with USC I only got 1200 min and free incoming calls.
Save your sanity, stay with PAYG

If you can't keep up with the payments then you will still be responsible for them. Most companies have an early termination fee that you will also have to pay. You will probably want to look into specific dollar amounts for fees before signing the contract.

Also, it depends on the phone, but you will more than likely be able to unlock it and use on another network.

Hi

I'm looking to go on contract with a network this will be my first contract as I've always gone pay as you go. Thay say i get the phone for free but will be billed 40€ per month. My question is what if after a few months i find i can't keep up the payments and need to cancel the contract. Could i then have the phone unlocked and use it as pay as you go again?

Thanks.