Shipping Charges

When does the Shipping Charge for shipped Fulfillment Orders (Income -> Orders -> Ship Order) eventually hit the GL Accrued Shipping Liability account (Admin -> Billing -> General Setup -> Shipping Liability)?

The shipping charge goes to the GL during the Orders to Invoices process (Income -> Orders -> Fulfillment Order -> Orders -> Invoices). If the order has a shipping charge on it, the system will add this shipping amount to the invoice and GL, even if a Freight Cost is added during shipping. The Freight Cost will be ignored. If there is no shipping charge on the order, but you do enter a Freight Cost during shipping, the Freight Cost will be added to the invoice and GL unless the setting Admin -> Billing -> Company Options -> Invoicing & Ordering ->Shipping -> If No Ship Charge On Order, Use Actual Ship Charge For Invoice is turned off. When this setting is off, the Freight Cost from the shipping process won't be used if no shipping charge is set on the order. This would allow you provide a free shipping option, but still retain info on what the Freight Costs are for outgoing shipments, though the entered Freight Costs won't hit the GL.

How does this account get relieved, and which account relieves the liability?

The Shipping Liability account is relieved when you pay a bill to your shipping carriers. You will need to select the Shipping Liability account as the offsetting account on vendor bills to your carriers. You can create manual GL entries to periodically move differences in shipping charges to customers vs actual shipping charges from your carriers to a sales or expense account.

As another option you can set up the Admin -> Billing -> General Setup -> Shipping Liability account as a sales account instead of a liability account, and then handle the charges to your carrier as a separate expense transaction.