AWB will pay or make credit available from last night to growers who used the company's harvest finance products for the 2012-13 crop.

The top-up payments range from $15 a tonne to $55 a tonne, depending on the wheat grade.

The payments – or available credit – mean those growers who used AWB's harvest finance will have received 80-88 per cent of current estimated pool returns for the 2012-13 crop.

AWB product manager Richard Williams said, while the top-up was not a guaranteed payment, it was reflective of the good progress in the company's marketing program for last harvest's crop.

AWB said it would close its wheat pools at 5pm today.

It also updated its EPRs for the pools, with eastern pool grades increasing by $5 a tonne, except for Australian Standard White and durum wheat grades.

The Australian Premium White wheat grade was now expected to return $342 a tonne, which ASW is forecast to end the season at $322 a tonne.