Co-signing for loans might be an option that you can look at when you have been subject to some major financial problem that has affected your credit score to such an extent that no one wants to lend you money.
As getting credit is essential for rebuilding your credit score this might be the only option available to get started again.
By getting the assistance of a co-signer you will get the benefit of that person's better credit record and that will help you to get a loan and one where you will possibly be able to get a reasonable interest rate.
There is a danger for both people with such an arrangement and even though your credit score might be low you don't want to add more bad information to your records if your co-signer fails to make payments.
Both you and the co-signer are responsible for the payments and any failure to make the payments required for the loan will result in damage being done to both yours and your co-signers credit scores.
On the other hand you can stand to make some gains with an arrangement where your co-signer has a good credit score and all the payments are made on time. This can help to boost your own credit score and help you to be able to arrange your own finance the next time you apply for a loan.
This is a good way to get started back on the road to recovery when there seems to be no other alternatives.
This can also show lenders that someone else has enough trust in your ability to make the repayments that they have risked their own credit score to help you out and some lenders will see that as a good sign to encourage them to lend you money once they have seen the co-signed loan paid off with no problems.