A flat fee, also referred to as a flat rate or a linear rate, refers to a pricing structure that charges a single fixed fee for a service, regardless of usage. Rarely, it may refer to a rate that does not vary with usage or time of use. Another term used is "flate", a hybrid of "flat" and "rate".

Most VoIP services are effectively flat-rate telephony services, since only the broadband internet fees must be paid for PC-to-PC calls, and the calls themselves are free. Some PC-to-telephone services, offer flat rates for national calls to landlines.

In the Sippy softswitch there is a possibility to organize "flat rate" scenario using "Free Minutes" plan (in the service plan).


Account refills his own balance to five dollars. Based on account "service plan" system will charge him to five dollars and allows him to use free minutes. When free minutes are finished an account will top-up his balance and the next_billing_time will be reseted which allows him to use free minutes once again.


1. Create tariff “Flat rate” without list of rates.

2. Create destination sets “Flat rate” with list of routes and prices of your vendor.

3. Create routing group “Flat rate” with appropriate list of connections and destination sets.

4. Create special service plan “Flate rate N min” with the following parameters:

  • Basic Tariff = “Flate rate” (which was created in the item 1);
  • Billing Cycle could be any (weekly, bi-weekly, monthly);
  • On Billing Failure = “Block all calls”;
  • Billing Type = “Pre-paid”;
  • Billing Day = “On 1st use”;
  • Service Charges = you need to specify some price (for free minutes) or set 0;
  • Minute Plans = you need to specify values like below(see image) or your own minute plan.

  • Also please use “Destination Patterns” table to upload prefixes which should be included/excluded for your minutes plan (see image with example);

5. Create account with the service plan “Flat rate N min” (as in example) and with “Flat rate” routing group.

In the section "Payments" of your account please choose option On Payment = "Restart Billing", because only in this case you will be able to make additional calls after top-up (in another case you will wait next billing period).

Then you need to Add funds = 1$ for account, so it will be charged after the first usage and account would be able to make 1 min call based on his minute plan which is in the service plan.

Also please note, there is no need to add prefixes to tariff if you will use minute plan with included prefixes in it. So when the minutes are over system would not allow you to make calls.