One key issue on CIL is whether a planning obligation can be a reason to grant permission.
Reg 123(3), as amended, says that where an obligation funds an infrastructure project or a type of infrastructure, then it cannot be taken into account if there have been five separate obligations on or after 6 April 2010 which relate to planning permissions in the charging authority's area and fund that project or type of project.
What is a planning obligation? Although we commonly describe the s.106 agreement as a planning obligation, it is actually the instrument containing the obligation or obligations and each covenant under s.106(1) is a separate obligation. So it's not enough just to count up the s.106 agreements.
Also, you can have more than one obligation for each payment. Take for example an obligation to make a payment towards schools. When drafting a planning obligation to make a payment it is common and good drafting not only to provide for the payment to be made on a certain date or event, but also to prohibit further development until the payment is made.
Each of those promises is a separate planning obligation, under s.106(1)(a) and (d) respectively. So, for very good reasons, one payment has used up two obligations under Reg 123. The alternative is just to include the promise to pay, and sue on that if the owner fails to pay. But what if the owner hasn't got the money? Or just include the prohibition, and seek the injunction until payment is made. But injunctions are discretionary remedies.