1026.21(e)(4) Small servicers.
(i) Exemption. A creditor, assignee, or servicer is exempt from the requirements of this section for mortgage loans serviced by a small servicer.
(ii) Small servicer defined. A small servicer is a servicer that either:
(A) Services, together with any affiliates, 5,000 or fewer mortgage loans, for all of which the servicer (or an affiliate) is the creditor or assignee; or
(B) Is a Housing Finance Agency, as defined in 24 CFR 266.5.
Since you only service loans that you own or originated (as in the case of the 20 that you originated then sold) and you service, together with any affiliates, fewer than 5,000 mortgages loans you are eligible for the exemption.