Got an overpayment notice, what now? - 12 months and counting

After 18 weeks of benefits I got a notice saying I must repay some of it. I have read a lot of threads here and could not find my exact situation. I cannot afford to repay it all at once. Are payment plans possible?

Thanks for writing this out. I went through something close to it 12 months ago, and it settled down once I kept a simple log of every call and form.