...asking creditors to agree to accept regular lower repayments towards all or part of your debts...
If you have a problem with long-term debt, then informally negotiated agreements with creditors may involve either:
Creditors may be prepared to agree to write-off part of what you owe them: any agreement to do so should be confirmed in writing.
An offer to creditors is calculated after working out affordable repayments based on personal circumstances, however this requires a supporting explanation. You also need to take account of whether creditors will agree to cap or penalties, charges and interest.
If your inability to make payments is temporary, perhaps as a result of a short term illness for example, creditors may agree to accept a repayments holiday for a limited period.