Shortening salutations to PBUH/SAW

بسم الله الرحمن الرحيم

“Indeed, Allah sends Ṣalāh upon the Prophet, and His angels (too). O you who believed, send Ṣalāh upon him and send Salām” [33:56]

Using symbols and signs like “ص, صعم, صلم, صليو, صلع, and صلعم” in place of “صلى الله عليه عليه وسلم” is in opposition to the Divine Command and the methodology of the Righteous Predecessors (Salaf Ṣāliḥīn). This ugly and innovated abbreviation is contrary to proper etiquette. It is such an absurd term that only an ignorant person would suffice with it.

al-Sakhāwi (D. 831-902) said while explaining Alfiyyah al-‘Irāqi

واجتنب أيها الكاتب ‌الرمز ‌لها أي للصلاة على رسول الله صلى الله عليه وسلم في خطك بأن تقتصر منها على حرفين ونحو ذلك فتكون منقوصة صورة كما يفعله الكسالي والجهلة من أبناء العجم غالبا وعوام الطلبة فيكتبون بدلا عن صلى الله عليه وسلم ص أو صم أو صلم أو صلعم فذلك لما فيه من نقص الأجر لنقص الكتابة خلاف الأولى [فتح المغيث (٣/ ٧١-٧٢)]

“Avoid, O writer, using a symbol for it, meaning for the salutations upon the Messenger of Allāh ﷺ in your writing by restricting it to two letters and the like, such that it becomes deficient in form as is done by the lazy and the ignorant among the non-Arabs mostly, and the common students. So they write ص، صم، صلم، صلعم instead of صلى الله عليه وسلم. For indeed that, due to the decrease in reward resulting from the decrease in writing, is contrary to what is best.” [Fatḥ al-Mughīth (3/71-72)]

[Taken from Dhikr e Muṣṭafā p. 65 by Shaykh Ghulām Muṣṭafā Ẓahīr Amanpurī]

I would recommend putting a text shortcut or using the ﷺ symbol. The minimum is to at least send Ṣalāh upon him in any manner (cf. al-Nasai 1292 with Hasan Isnad). The best wordings are those mentioned by the sunnah. If a person is still so lazy then he must at least say it by his tongue as shaykh Ibn ‘Uthaymeen mentioned