http://www.dswd.gov.ph/index.php/cat...ce-for-minors-
WHAT ARE THE REQUIREMENTS IN SECURING A TRAVEL CLEARANCE?
* Duly accomplished application form;
* Photocopy of the birth certificate or passport of the minor;
* A written consent of both parents or the solo parent or the legal guardian permitting the child to travel alone or with someone else to a foreign country;
* Photocopy of passport of traveling companion, for accompanied minors.
* As appropriate,
1. a photocopy of the marriage certificate of the minors parents or;
2. a photocopy of the certificate of legal guardianship of the minor or;
3. a photocopy of the solo parent identification card from the municipal social welfare
4. in the case of an illegitimate minor, a certificate of no marriage from the local civil registrar;
5. in the case of a deceased parent, a photocopy of the death certificate;
* Two colored passport size photos of the minor taken within the last 6 months.
**** I think your mum can secure a travel clearance from dswd since you said u have a legal paper stating she is the legal guardian of your son and who will travel with him to uk...
the travel clearance can be one of the important supporting documents
before you apply for your sons visa.*****